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What Are the Elements of a Good Hypothesis?

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A hypothesis is an educated guess or prediction of what will happen. In science, a hypothesis proposes a relationship between factors called variables. A good hypothesis relates an independent variable and a dependent variable. The effect on the dependent variable depends on or is determined by what happens when you change the independent variable . While you could consider any prediction of an outcome to be a type of hypothesis, a good hypothesis is one you can test using the scientific method. In other words, you want to propose a hypothesis to use as the basis for an experiment.

Cause and Effect or 'If, Then' Relationships

A good experimental hypothesis can be written as an if, then statement to establish cause and effect on the variables. If you make a change to the independent variable, then the dependent variable will respond. Here's an example of a hypothesis:

If you increase the duration of light, (then) corn plants will grow more each day.

The hypothesis establishes two variables, length of light exposure, and the rate of plant growth. An experiment could be designed to test whether the rate of growth depends on the duration of light. The duration of light is the independent variable, which you can control in an experiment . The rate of plant growth is the dependent variable, which you can measure and record as data in an experiment.

Key Points of Hypothesis

When you have an idea for a hypothesis, it may help to write it out in several different ways. Review your choices and select a hypothesis that accurately describes what you are testing.

• Does the hypothesis relate an independent and dependent variable? Can you identify the variables?
• Can you test the hypothesis? In other words, could you design an experiment that would allow you to establish or disprove a relationship between the variables?
• Would your experiment be safe and ethical?
• Is there a simpler or more precise way to state the hypothesis? If so, rewrite it.

What If the Hypothesis Is Incorrect?

It's not wrong or bad if the hypothesis is not supported or is incorrect. Actually, this outcome may tell you more about a relationship between the variables than if the hypothesis is supported. You may intentionally write your hypothesis as a null hypothesis or no-difference hypothesis to establish a relationship between the variables.

For example, the hypothesis:

The rate of corn plant growth does not depend on the duration of light.

This can be tested by exposing corn plants to different length "days" and measuring the rate of plant growth. A statistical test can be applied to measure how well the data support the hypothesis. If the hypothesis is not supported, then you have evidence of a relationship between the variables. It's easier to establish cause and effect by testing whether "no effect" is found. Alternatively, if the null hypothesis is supported, then you have shown the variables are not related. Either way, your experiment is a success.

Need more examples of how to write a hypothesis ? Here you go:

• If you turn out all the lights, you will fall asleep faster. (Think: How would you test it?)
• If you drop different objects, they will fall at the same rate.
• If you eat only fast food, then you will gain weight.
• If you use cruise control, then your car will get better gas mileage.
• If you apply a top coat, then your manicure will last longer.
• If you turn the lights on and off rapidly, then the bulb will burn out faster.
• What Is a Testable Hypothesis?
• What Are Examples of a Hypothesis?
• What Is a Hypothesis? (Science)
• Scientific Hypothesis Examples
• Six Steps of the Scientific Method
• Scientific Method Flow Chart
• Null Hypothesis Examples
• Understanding Simple vs Controlled Experiments
• Scientific Method Vocabulary Terms
• What Is a Controlled Experiment?
• Scientific Variable
• What Is an Experimental Constant?
• What Is the Difference Between a Control Variable and Control Group?
• DRY MIX Experiment Variables Acronym
• Random Error vs. Systematic Error
• The Role of a Controlled Variable in an Experiment

How to Write a Hypothesis in 6 Steps, With Examples

A hypothesis is a statement that explains the predictions and reasoning of your research—an “educated guess” about how your scientific experiments will end. As a fundamental part of the scientific method, a good hypothesis is carefully written, but even the simplest ones can be difficult to put into words. 

Want to know how to write a hypothesis for your academic paper ? Below we explain the different types of hypotheses, what a good hypothesis requires, the steps to write your own, and plenty of examples.

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What is a hypothesis? 

One of our 10 essential words for university success , a hypothesis is one of the earliest stages of the scientific method. It’s essentially an educated guess—based on observations—of what the results of your experiment or research will be. 

Some hypothesis examples include:

• If I water plants daily they will grow faster.
• Adults can more accurately guess the temperature than children can. 
• Butterflies prefer white flowers to orange ones.

If you’ve noticed that watering your plants every day makes them grow faster, your hypothesis might be “plants grow better with regular watering.” From there, you can begin experiments to test your hypothesis; in this example, you might set aside two plants, water one but not the other, and then record the results to see the differences. 

The language of hypotheses always discusses variables , or the elements that you’re testing. Variables can be objects, events, concepts, etc.—whatever is observable. 

There are two types of variables: independent and dependent. Independent variables are the ones that you change for your experiment, whereas dependent variables are the ones that you can only observe. In the above example, our independent variable is how often we water the plants and the dependent variable is how well they grow. 

Hypotheses determine the direction and organization of your subsequent research methods, and that makes them a big part of writing a research paper . Ultimately the reader wants to know whether your hypothesis was proven true or false, so it must be written clearly in the introduction and/or abstract of your paper. 

7 examples of hypotheses

Depending on the nature of your research and what you expect to find, your hypothesis will fall into one or more of the seven main categories. Keep in mind that these categories are not exclusive, so the same hypothesis might qualify as several different types. 

1 Simple hypothesis

A simple hypothesis suggests only the relationship between two variables: one independent and one dependent. 

• If you stay up late, then you feel tired the next day. 
• Turning off your phone makes it charge faster. 

2 Complex hypothesis

A complex hypothesis suggests the relationship between more than two variables, for example, two independents and one dependent, or vice versa. 

• People who both (1) eat a lot of fatty foods and (2) have a family history of health problems are more likely to develop heart diseases. 
• Older people who live in rural areas are happier than younger people who live in rural areas. 

3 Null hypothesis

A null hypothesis, abbreviated as H 0 , suggests that there is no relationship between variables. 

• There is no difference in plant growth when using either bottled water or tap water. 
• Professional psychics do not win the lottery more than other people. 

4 Alternative hypothesis

An alternative hypothesis, abbreviated as H 1 or H A , is used in conjunction with a null hypothesis. It states the opposite of the null hypothesis, so that one and only one must be true. 

• Plants grow better with bottled water than tap water. 
• Professional psychics win the lottery more than other people. 

5 Logical hypothesis

A logical hypothesis suggests a relationship between variables without actual evidence. Claims are instead based on reasoning or deduction, but lack actual data.  

• An alien raised on Venus would have trouble breathing in Earth’s atmosphere. 
• Dinosaurs with sharp, pointed teeth were probably carnivores. 

6 Empirical hypothesis

An empirical hypothesis, also known as a “working hypothesis,” is one that is currently being tested. Unlike logical hypotheses, empirical hypotheses rely on concrete data. 

• Customers at restaurants will tip the same even if the wait staff’s base salary is raised. 
• Washing your hands every hour can reduce the frequency of illness. 

7 Statistical hypothesis

A statistical hypothesis is when you test only a sample of a population and then apply statistical evidence to the results to draw a conclusion about the entire population. Instead of testing everything , you test only a portion and generalize the rest based on preexisting data. 

• In humans, the birth-gender ratio of males to females is 1.05 to 1.00.  
• Approximately 2% of the world population has natural red hair. 

What makes a good hypothesis?

No matter what you’re testing, a good hypothesis is written according to the same guidelines. In particular, keep these five characteristics in mind: 

Cause and effect

Hypotheses always include a cause-and-effect relationship where one variable causes another to change (or not change if you’re using a null hypothesis). This can best be reflected as an if-then statement: If one variable occurs, then another variable changes. 

Testable prediction

Most hypotheses are designed to be tested (with the exception of logical hypotheses). Before committing to a hypothesis, make sure you’re actually able to conduct experiments on it. Choose a testable hypothesis with an independent variable that you have absolute control over. 

Independent and dependent variables

Define your variables in your hypothesis so your readers understand the big picture. You don’t have to specifically say which ones are independent and dependent variables, but you definitely want to mention them all. 

Candid language

Writing can easily get convoluted, so make sure your hypothesis remains as simple and clear as possible. Readers use your hypothesis as a contextual pillar to unify your entire paper, so there should be no confusion or ambiguity. If you’re unsure about your phrasing, try reading your hypothesis to a friend to see if they understand. 

Adherence to ethics

It’s not always about what you can test, but what you should test. Avoid hypotheses that require questionable or taboo experiments to keep ethics (and therefore, credibility) intact.

How to write a hypothesis in 6 steps

1 ask a question.

Curiosity has inspired some of history’s greatest scientific achievements, so a good place to start is to ask yourself questions about the world around you. Why are things the way they are? What causes the factors you see around you? If you can, choose a research topic that you’re interested in so your curiosity comes naturally. 

2 Conduct preliminary research

Next, collect some background information on your topic. How much background information you need depends on what you’re attempting. It could require reading several books, or it could be as simple as performing a web search for a quick answer. You don’t necessarily have to prove or disprove your hypothesis at this stage; rather, collect only what you need to prove or disprove it yourself. 

3 Define your variables

Once you have an idea of what your hypothesis will be, select which variables are independent and which are dependent. Remember that independent variables can only be factors that you have absolute control over, so consider the limits of your experiment before finalizing your hypothesis. 

4 Phrase it as an if-then statement

When writing a hypothesis, it helps to phrase it using an if-then format, such as, “ If I water a plant every day, then it will grow better.” This format can get tricky when dealing with multiple variables, but in general, it’s a reliable method for expressing the cause-and-effect relationship you’re testing. 

5  Collect data to support your hypothesis

A hypothesis is merely a means to an end. The priority of any scientific research is the conclusion. Once you have your hypothesis laid out and your variables chosen, you can then begin your experiments. Ideally, you’ll collect data to support your hypothesis, but don’t worry if your research ends up proving it wrong—that’s all part of the scientific method. 

6 Write with confidence

Last, you’ll want to record your findings in a research paper for others to see. This requires a bit of writing know-how, quite a different skill set than conducting experiments. 

That’s where Grammarly can be a major help; our writing suggestions point out not only grammar and spelling mistakes , but also new word choices and better phrasing. While you write, Grammarly automatically recommends optimal language and highlights areas where readers might get confused, ensuring that your hypothesis—and your final paper—are clear and polished.

How to Write a Hypothesis? Types and Examples 

All research studies involve the use of the scientific method, which is a mathematical and experimental technique used to conduct experiments by developing and testing a hypothesis or a prediction about an outcome. Simply put, a hypothesis is a suggested solution to a problem. It includes elements that are expressed in terms of relationships with each other to explain a condition or an assumption that hasn’t been verified using facts. 1 The typical steps in a scientific method include developing such a hypothesis, testing it through various methods, and then modifying it based on the outcomes of the experiments.  

A research hypothesis can be defined as a specific, testable prediction about the anticipated results of a study. 2 Hypotheses help guide the research process and supplement the aim of the study. After several rounds of testing, hypotheses can help develop scientific theories. 3 Hypotheses are often written as if-then statements. 

Here are two hypothesis examples: 

Dandelions growing in nitrogen-rich soils for two weeks develop larger leaves than those in nitrogen-poor soils because nitrogen stimulates vegetative growth. 4  

If a company offers flexible work hours, then their employees will be happier at work. 5  

Table of Contents

• What is a hypothesis? 
• Types of hypotheses 
• Characteristics of a hypothesis 
• Functions of a hypothesis 
• How to write a hypothesis 
• Hypothesis examples 
• Frequently asked questions 

What is a hypothesis?

A hypothesis expresses an expected relationship between variables in a study and is developed before conducting any research. Hypotheses are not opinions but rather are expected relationships based on facts and observations. They help support scientific research and expand existing knowledge. An incorrectly formulated hypothesis can affect the entire experiment leading to errors in the results so it’s important to know how to formulate a hypothesis and develop it carefully.

A few sources of a hypothesis include observations from prior studies, current research and experiences, competitors, scientific theories, and general conditions that can influence people. Figure 1 depicts the different steps in a research design and shows where exactly in the process a hypothesis is developed. 4  

There are seven different types of hypotheses—simple, complex, directional, nondirectional, associative and causal, null, and alternative. 

Types of hypotheses

The seven types of hypotheses are listed below: 5 , 6,7  

• Simple : Predicts the relationship between a single dependent variable and a single independent variable. 

Example: Exercising in the morning every day will increase your productivity.  

• Complex : Predicts the relationship between two or more variables. 

Example: Spending three hours or more on social media daily will negatively affect children’s mental health and productivity, more than that of adults.  

• Directional : Specifies the expected direction to be followed and uses terms like increase, decrease, positive, negative, more, or less. 

Example: The inclusion of intervention X decreases infant mortality compared to the original treatment.  

• Non-directional : Does not predict the exact direction, nature, or magnitude of the relationship between two variables but rather states the existence of a relationship. This hypothesis may be used when there is no underlying theory or if findings contradict prior research. 

Example: Cats and dogs differ in the amount of affection they express.  

• Associative and causal : An associative hypothesis suggests an interdependency between variables, that is, how a change in one variable changes the other.  

Example: There is a positive association between physical activity levels and overall health.  

A causal hypothesis, on the other hand, expresses a cause-and-effect association between variables. 

Example: Long-term alcohol use causes liver damage.  

• Null : Claims that the original hypothesis is false by showing that there is no relationship between the variables. 

Example: Sleep duration does not have any effect on productivity.  

• Alternative : States the opposite of the null hypothesis, that is, a relationship exists between two variables. 

Example: Sleep duration affects productivity.  

Characteristics of a hypothesis

So, what makes a good hypothesis? Here are some important characteristics of a hypothesis. 8,9  

• Testable : You must be able to test the hypothesis using scientific methods to either accept or reject the prediction. 
• Falsifiable : It should be possible to collect data that reject rather than support the hypothesis. 
• Logical : Hypotheses shouldn’t be a random guess but rather should be based on previous theories, observations, prior research, and logical reasoning. 
• Positive : The hypothesis statement about the existence of an association should be positive, that is, it should not suggest that an association does not exist. Therefore, the language used and knowing how to phrase a hypothesis is very important. 
• Clear and accurate : The language used should be easily comprehensible and use correct terminology. 
• Relevant : The hypothesis should be relevant and specific to the research question. 
• Structure : Should include all the elements that make a good hypothesis: variables, relationship, and outcome. 

Functions of a hypothesis

The following list mentions some important functions of a hypothesis: 1  

• Maintains the direction and progress of the research. 
• Expresses the important assumptions underlying the proposition in a single statement. 
• Establishes a suitable context for researchers to begin their investigation and for readers who are referring to the final report. 
• Provides an explanation for the occurrence of a specific phenomenon. 
• Ensures selection of appropriate and accurate facts necessary and relevant to the research subject. 

To summarize, a hypothesis provides the conceptual elements that complete the known data, conceptual relationships that systematize unordered elements, and conceptual meanings and interpretations that explain the unknown phenomena. 1  

How to write a hypothesis

Listed below are the main steps explaining how to write a hypothesis. 2,4,5  

• Make an observation and identify variables : Observe the subject in question and try to recognize a pattern or a relationship between the variables involved. This step provides essential background information to begin your research.  

For example, if you notice that an office’s vending machine frequently runs out of a specific snack, you may predict that more people in the office choose that snack over another. 

• Identify the main research question : After identifying a subject and recognizing a pattern, the next step is to ask a question that your hypothesis will answer.  

For example, after observing employees’ break times at work, you could ask “why do more employees take breaks in the morning rather than in the afternoon?” 

• Conduct some preliminary research to ensure originality and novelty : Your initial answer, which is your hypothesis, to the question is based on some pre-existing information about the subject. However, to ensure that your hypothesis has not been asked before or that it has been asked but rejected by other researchers you would need to gather additional information.  

For example, based on your observations you might state a hypothesis that employees work more efficiently when the air conditioning in the office is set at a lower temperature. However, during your preliminary research you find that this hypothesis was proven incorrect by a prior study. 

• Develop a general statement : After your preliminary research has confirmed the originality of your proposed answer, draft a general statement that includes all variables, subjects, and predicted outcome. The statement could be if/then or declarative.  
• Finalize the hypothesis statement : Use the PICOT model, which clarifies how to word a hypothesis effectively, when finalizing the statement. This model lists the important components required to write a hypothesis. 

P opulation: The specific group or individual who is the main subject of the research 

I nterest: The main concern of the study/research question 

C omparison: The main alternative group 

O utcome: The expected results  

T ime: Duration of the experiment 

Once you’ve finalized your hypothesis statement you would need to conduct experiments to test whether the hypothesis is true or false. 

Hypothesis examples

The following table provides examples of different types of hypotheses. 10 ,11  

Key takeaways  

Here’s a summary of all the key points discussed in this article about how to write a hypothesis. 

• A hypothesis is an assumption about an association between variables made based on limited evidence, which should be tested. 
• A hypothesis has four parts—the research question, independent variable, dependent variable, and the proposed relationship between the variables.   
• The statement should be clear, concise, testable, logical, and falsifiable. 
• There are seven types of hypotheses—simple, complex, directional, non-directional, associative and causal, null, and alternative. 
• A hypothesis provides a focus and direction for the research to progress. 
• A hypothesis plays an important role in the scientific method by helping to create an appropriate experimental design. 

Frequently asked questions

Hypotheses and research questions have different objectives and structure. The following table lists some major differences between the two. 9  

Here are a few examples to differentiate between a research question and hypothesis. 

Yes, here’s a simple checklist to help you gauge the effectiveness of your hypothesis. 9   1. When writing a hypothesis statement, check if it:  2. Predicts the relationship between the stated variables and the expected outcome.  3. Uses simple and concise language and is not wordy.  4. Does not assume readers’ knowledge about the subject.  5. Has observable, falsifiable, and testable results. 

As mentioned earlier in this article, a hypothesis is an assumption or prediction about an association between variables based on observations and simple evidence. These statements are usually generic. Research objectives, on the other hand, are more specific and dictated by hypotheses. The same hypothesis can be tested using different methods and the research objectives could be different in each case.     For example, Louis Pasteur observed that food lasts longer at higher altitudes, reasoned that it could be because the air at higher altitudes is cleaner (with fewer or no germs), and tested the hypothesis by exposing food to air cleaned in the laboratory. 12 Thus, a hypothesis is predictive—if the reasoning is correct, X will lead to Y—and research objectives are developed to test these predictions. 

Null hypothesis testing is a method to decide between two assumptions or predictions between variables (null and alternative hypotheses) in a statistical relationship in a sample. The null hypothesis, denoted as H 0 , claims that no relationship exists between variables in a population and any relationship in the sample reflects a sampling error or occurrence by chance. The alternative hypothesis, denoted as H 1 , claims that there is a relationship in the population. In every study, researchers need to decide whether the relationship in a sample occurred by chance or reflects a relationship in the population. This is done by hypothesis testing using the following steps: 13   1. Assume that the null hypothesis is true.  2. Determine how likely the sample relationship would be if the null hypothesis were true. This probability is called the p value.  3. If the sample relationship would be extremely unlikely, reject the null hypothesis and accept the alternative hypothesis. If the relationship would not be unlikely, accept the null hypothesis. 

To summarize, researchers should know how to write a good hypothesis to ensure that their research progresses in the required direction. A hypothesis is a testable prediction about any behavior or relationship between variables, usually based on facts and observation, and states an expected outcome.  

We hope this article has provided you with essential insight into the different types of hypotheses and their functions so that you can use them appropriately in your next research project. 

References  

• Dalen, DVV. The function of hypotheses in research. Proquest website. Accessed April 8, 2024. https://www.proquest.com/docview/1437933010?pq-origsite=gscholar&fromopenview=true&sourcetype=Scholarly%20Journals&imgSeq=1  
• McLeod S. Research hypothesis in psychology: Types & examples. SimplyPsychology website. Updated December 13, 2023. Accessed April 9, 2024. https://www.simplypsychology.org/what-is-a-hypotheses.html  
• Scientific method. Britannica website. Updated March 14, 2024. Accessed April 9, 2024. https://www.britannica.com/science/scientific-method  
• The hypothesis in science writing. Accessed April 10, 2024. https://berks.psu.edu/sites/berks/files/campus/HypothesisHandout_Final.pdf  
• How to develop a hypothesis (with elements, types, and examples). Indeed.com website. Updated February 3, 2023. Accessed April 10, 2024. https://www.indeed.com/career-advice/career-development/how-to-write-a-hypothesis  
• Types of research hypotheses. Excelsior online writing lab. Accessed April 11, 2024. https://owl.excelsior.edu/research/research-hypotheses/types-of-research-hypotheses/  
• What is a research hypothesis: how to write it, types, and examples. Researcher.life website. Published February 8, 2023. Accessed April 11, 2024. https://researcher.life/blog/article/how-to-write-a-research-hypothesis-definition-types-examples/  
• Developing a hypothesis. Pressbooks website. Accessed April 12, 2024. https://opentext.wsu.edu/carriecuttler/chapter/developing-a-hypothesis/  
• What is and how to write a good hypothesis in research. Elsevier author services website. Accessed April 12, 2024. https://scientific-publishing.webshop.elsevier.com/manuscript-preparation/what-how-write-good-hypothesis-research/  
• How to write a great hypothesis. Verywellmind website. Updated March 12, 2023. Accessed April 13, 2024. https://www.verywellmind.com/what-is-a-hypothesis-2795239  
• 15 Hypothesis examples. Helpfulprofessor.com Published September 8, 2023. Accessed March 14, 2024. https://helpfulprofessor.com/hypothesis-examples/ 
• Editage insights. What is the interconnectivity between research objectives and hypothesis? Published February 24, 2021. Accessed April 13, 2024. https://www.editage.com/insights/what-is-the-interconnectivity-between-research-objectives-and-hypothesis  
• Understanding null hypothesis testing. BCCampus open publishing. Accessed April 16, 2024. https://opentextbc.ca/researchmethods/chapter/understanding-null-hypothesis-testing/#:~:text=In%20null%20hypothesis%20testing%2C%20this,said%20to%20be%20statistically%20significant  

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2.4 Developing a Hypothesis

Learning objectives.

• Distinguish between a theory and a hypothesis.
• Discover how theories are used to generate hypotheses and how the results of studies can be used to further inform theories.
• Understand the characteristics of a good hypothesis.

Theories and Hypotheses

Before describing how to develop a hypothesis it is imporant to distinguish betwee a theory and a hypothesis. A  theory  is a coherent explanation or interpretation of one or more phenomena. Although theories can take a variety of forms, one thing they have in common is that they go beyond the phenomena they explain by including variables, structures, processes, functions, or organizing principles that have not been observed directly. Consider, for example, Zajonc’s theory of social facilitation and social inhibition. He proposed that being watched by others while performing a task creates a general state of physiological arousal, which increases the likelihood of the dominant (most likely) response. So for highly practiced tasks, being watched increases the tendency to make correct responses, but for relatively unpracticed tasks, being watched increases the tendency to make incorrect responses. Notice that this theory—which has come to be called drive theory—provides an explanation of both social facilitation and social inhibition that goes beyond the phenomena themselves by including concepts such as “arousal” and “dominant response,” along with processes such as the effect of arousal on the dominant response.

Outside of science, referring to an idea as a theory often implies that it is untested—perhaps no more than a wild guess. In science, however, the term theory has no such implication. A theory is simply an explanation or interpretation of a set of phenomena. It can be untested, but it can also be extensively tested, well supported, and accepted as an accurate description of the world by the scientific community. The theory of evolution by natural selection, for example, is a theory because it is an explanation of the diversity of life on earth—not because it is untested or unsupported by scientific research. On the contrary, the evidence for this theory is overwhelmingly positive and nearly all scientists accept its basic assumptions as accurate. Similarly, the “germ theory” of disease is a theory because it is an explanation of the origin of various diseases, not because there is any doubt that many diseases are caused by microorganisms that infect the body.

A  hypothesis , on the other hand, is a specific prediction about a new phenomenon that should be observed if a particular theory is accurate. It is an explanation that relies on just a few key concepts. Hypotheses are often specific predictions about what will happen in a particular study. They are developed by considering existing evidence and using reasoning to infer what will happen in the specific context of interest. Hypotheses are often but not always derived from theories. So a hypothesis is often a prediction based on a theory but some hypotheses are a-theoretical and only after a set of observations have been made, is a theory developed. This is because theories are broad in nature and they explain larger bodies of data. So if our research question is really original then we may need to collect some data and make some observation before we can develop a broader theory.

Theories and hypotheses always have this  if-then  relationship. “ If   drive theory is correct,  then  cockroaches should run through a straight runway faster, and a branching runway more slowly, when other cockroaches are present.” Although hypotheses are usually expressed as statements, they can always be rephrased as questions. “Do cockroaches run through a straight runway faster when other cockroaches are present?” Thus deriving hypotheses from theories is an excellent way of generating interesting research questions.

But how do researchers derive hypotheses from theories? One way is to generate a research question using the techniques discussed in this chapter  and then ask whether any theory implies an answer to that question. For example, you might wonder whether expressive writing about positive experiences improves health as much as expressive writing about traumatic experiences. Although this  question  is an interesting one  on its own, you might then ask whether the habituation theory—the idea that expressive writing causes people to habituate to negative thoughts and feelings—implies an answer. In this case, it seems clear that if the habituation theory is correct, then expressive writing about positive experiences should not be effective because it would not cause people to habituate to negative thoughts and feelings. A second way to derive hypotheses from theories is to focus on some component of the theory that has not yet been directly observed. For example, a researcher could focus on the process of habituation—perhaps hypothesizing that people should show fewer signs of emotional distress with each new writing session.

Among the very best hypotheses are those that distinguish between competing theories. For example, Norbert Schwarz and his colleagues considered two theories of how people make judgments about themselves, such as how assertive they are (Schwarz et al., 1991) [1] . Both theories held that such judgments are based on relevant examples that people bring to mind. However, one theory was that people base their judgments on the  number  of examples they bring to mind and the other was that people base their judgments on how  easily  they bring those examples to mind. To test these theories, the researchers asked people to recall either six times when they were assertive (which is easy for most people) or 12 times (which is difficult for most people). Then they asked them to judge their own assertiveness. Note that the number-of-examples theory implies that people who recalled 12 examples should judge themselves to be more assertive because they recalled more examples, but the ease-of-examples theory implies that participants who recalled six examples should judge themselves as more assertive because recalling the examples was easier. Thus the two theories made opposite predictions so that only one of the predictions could be confirmed. The surprising result was that participants who recalled fewer examples judged themselves to be more assertive—providing particularly convincing evidence in favor of the ease-of-retrieval theory over the number-of-examples theory.

Theory Testing

The primary way that scientific researchers use theories is sometimes called the hypothetico-deductive method  (although this term is much more likely to be used by philosophers of science than by scientists themselves). A researcher begins with a set of phenomena and either constructs a theory to explain or interpret them or chooses an existing theory to work with. He or she then makes a prediction about some new phenomenon that should be observed if the theory is correct. Again, this prediction is called a hypothesis. The researcher then conducts an empirical study to test the hypothesis. Finally, he or she reevaluates the theory in light of the new results and revises it if necessary. This process is usually conceptualized as a cycle because the researcher can then derive a new hypothesis from the revised theory, conduct a new empirical study to test the hypothesis, and so on. As  Figure 2.2  shows, this approach meshes nicely with the model of scientific research in psychology presented earlier in the textbook—creating a more detailed model of “theoretically motivated” or “theory-driven” research.

Figure 2.2 Hypothetico-Deductive Method Combined With the General Model of Scientific Research in Psychology Together they form a model of theoretically motivated research.

As an example, let us consider Zajonc’s research on social facilitation and inhibition. He started with a somewhat contradictory pattern of results from the research literature. He then constructed his drive theory, according to which being watched by others while performing a task causes physiological arousal, which increases an organism’s tendency to make the dominant response. This theory predicts social facilitation for well-learned tasks and social inhibition for poorly learned tasks. He now had a theory that organized previous results in a meaningful way—but he still needed to test it. He hypothesized that if his theory was correct, he should observe that the presence of others improves performance in a simple laboratory task but inhibits performance in a difficult version of the very same laboratory task. To test this hypothesis, one of the studies he conducted used cockroaches as subjects (Zajonc, Heingartner, & Herman, 1969) [2] . The cockroaches ran either down a straight runway (an easy task for a cockroach) or through a cross-shaped maze (a difficult task for a cockroach) to escape into a dark chamber when a light was shined on them. They did this either while alone or in the presence of other cockroaches in clear plastic “audience boxes.” Zajonc found that cockroaches in the straight runway reached their goal more quickly in the presence of other cockroaches, but cockroaches in the cross-shaped maze reached their goal more slowly when they were in the presence of other cockroaches. Thus he confirmed his hypothesis and provided support for his drive theory. (Zajonc also showed that drive theory existed in humans (Zajonc & Sales, 1966) [3] in many other studies afterward).

Incorporating Theory into Your Research

When you write your research report or plan your presentation, be aware that there are two basic ways that researchers usually include theory. The first is to raise a research question, answer that question by conducting a new study, and then offer one or more theories (usually more) to explain or interpret the results. This format works well for applied research questions and for research questions that existing theories do not address. The second way is to describe one or more existing theories, derive a hypothesis from one of those theories, test the hypothesis in a new study, and finally reevaluate the theory. This format works well when there is an existing theory that addresses the research question—especially if the resulting hypothesis is surprising or conflicts with a hypothesis derived from a different theory.

To use theories in your research will not only give you guidance in coming up with experiment ideas and possible projects, but it lends legitimacy to your work. Psychologists have been interested in a variety of human behaviors and have developed many theories along the way. Using established theories will help you break new ground as a researcher, not limit you from developing your own ideas.

Characteristics of a Good Hypothesis

There are three general characteristics of a good hypothesis. First, a good hypothesis must be testable and falsifiable . We must be able to test the hypothesis using the methods of science and if you’ll recall Popper’s falsifiability criterion, it must be possible to gather evidence that will disconfirm the hypothesis if it is indeed false. Second, a good hypothesis must be  logical. As described above, hypotheses are more than just a random guess. Hypotheses should be informed by previous theories or observations and logical reasoning. Typically, we begin with a broad and general theory and use  deductive reasoning to generate a more specific hypothesis to test based on that theory. Occasionally, however, when there is no theory to inform our hypothesis, we use  inductive reasoning  which involves using specific observations or research findings to form a more general hypothesis. Finally, the hypothesis should be  positive.  That is, the hypothesis should make a positive statement about the existence of a relationship or effect, rather than a statement that a relationship or effect does not exist. As scientists, we don’t set out to show that relationships do not exist or that effects do not occur so our hypotheses should not be worded in a way to suggest that an effect or relationship does not exist. The nature of science is to assume that something does not exist and then seek to find evidence to prove this wrong, to show that really it does exist. That may seem backward to you but that is the nature of the scientific method. The underlying reason for this is beyond the scope of this chapter but it has to do with statistical theory.

Key Takeaways

• A theory is broad in nature and explains larger bodies of data. A hypothesis is more specific and makes a prediction about the outcome of a particular study.
• Working with theories is not “icing on the cake.” It is a basic ingredient of psychological research.
• Like other scientists, psychologists use the hypothetico-deductive method. They construct theories to explain or interpret phenomena (or work with existing theories), derive hypotheses from their theories, test the hypotheses, and then reevaluate the theories in light of the new results.
• Practice: Find a recent empirical research report in a professional journal. Read the introduction and highlight in different colors descriptions of theories and hypotheses.
• Schwarz, N., Bless, H., Strack, F., Klumpp, G., Rittenauer-Schatka, H., & Simons, A. (1991). Ease of retrieval as information: Another look at the availability heuristic.  Journal of Personality and Social Psychology, 61 , 195–202. ↵
• Zajonc, R. B., Heingartner, A., & Herman, E. M. (1969). Social enhancement and impairment of performance in the cockroach.  Journal of Personality and Social Psychology, 13 , 83–92. ↵
• Zajonc, R.B. & Sales, S.M. (1966). Social facilitation of dominant and subordinate responses. Journal of Experimental Social Psychology, 2 , 160-168. ↵

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What makes a good hypothesis?

Formulating a good hypothesis is the backbone of the scientific method.

A hypothesis is a precise and testable statement of what a researcher predicts will be the outcome of a study. This usually involves proposing a relationship between two or more variables.

Verifying a hypothesis, also sometimes referred to as a working statement , requires using the scientific method , usually by designing an experiment.

For instance, one common adage is ‘an apple a day keeps the doctor away’. If we use this aphorism as our hypothesis then we can make a prediction that consuming at least one apple per day should result in fewer visits to the doctor than the general population that eats apples sparingly or never.

In 2015 , researchers at Dartmouth College, the University of Michigan School of Nursing, and the Veteran Affairs Medical Center in White River actually investigated this hypothesis. They combed national nutrition data collected from nearly 8,400 men and women — 753 of whom ate an apple a day. The study found that “evidence does not support that an apple a day keeps the doctor away; however, the small fraction of US adults who eat an apple a day do appear to use fewer prescription medications.”

So perhaps there’s a glimmer of truth to this hypothesis, but not necessarily because apples are some miracle foods. It could be that people who eat apples every day also consume other fresh produce and less processed foods than the general population, a diet that helps to prevent obesity, a huge risk factor for a myriad of illnesses such as hypertension and diabetes that require prescription medication. This is why hypotheses need to be defined as precisely and as narrowly as possible in order to isolate confounding effects.

Types of hypothesis

The ‘apple a day’ study is an example of an alternative hypothesis , which states that there is a relationship between two variables being studied, the daily apple consumption and visits to the GP. One variable, called the independent variable , has an effect on the other, known as the dependent variable . The independent variable is what you change and the dependent variable is what you measure. For example, if I am measuring how a plant grows with different fertilizers, the fertilizers are what I can change freely (independent) while the plant’s growth would be dependent on what it is given. In order for an alternative hypothesis to be validated, the results have to have statistical significance in order to rule out chance.

Examples of alternative hypotheses:

• Dogs wag their tails when they’re happy.
• The accumulation of greenhouse gases in the atmosphere raises global average temperature.
• Wearing a seatbelt reduces traffic-related fatalities.
• Students who attend class earn higher scores than students who skip class.
• People exposed to higher levels of UV light have a higher incidence of skin cancer than the general population.

Another common type of hypothesis used in science is the null hypothesis , which states that there is no relationship between two variables. This means that controlling one variable has no effect on the other. Any results are due to chance and thus pursuing a cause-effect relationship between the two variables is futile.

The null hypothesis is the polar opposite of the alternative hypothesis since they contain opposing viewpoints. In fact, the latter is called this way because it is an alternative to the null hypothesis. An apple a day doesn’t keep the doctor away, you could propose if you were designing a null hypothesis experiment.

Examples of null hypotheses:

• Taking an aspirin a day doesn’t reduce the risk of a heart attack.
• Playing classical music doesn’t help plants grow more biomass.
• Vaccines don’t cause autism.
• Hyperactivity is unrelated to sugar consumption.

The acceptance of the alternative hypothesis, often denoted by H 1 , depends on the rejection of the null hypothesis (H 0 ). A null hypothesis can never be proven, it can only be rejected. To test a null hypothesis and determine whether the observed data is not due to change or the manipulation of data, scientists employ a significance test.

Rejecting the null hypothesis does not necessarily imply that a study did not produce the required results. Instead, it sets the stage for further experimentation to see if a relationship between the two variables truly exists.

For instance, say a scientist proposes a null hypothesis stating that “the rate of plant growth is not affected by sunlight.” One way to investigate this conjecture would be to monitor a random sample of plants grown with or without sunlight. You then measure the average mass of each group of plants and if there’s a statistically significant difference in the observed change, then the null hypothesis is rejected. Consequently, the alternate hypothesis that “plant growth is affected by sunlight” is accepted, then scientists can perform further research into the effects of different wavelengths of light or intensities of light on plant growth.

At this point, you might be wondering why we need the null hypothesis. Why not propose and test an alternate hypothesis and see if it is true? One explanation is that science cannot provide absolute proofs, but rather approximations. The scientific method cannot explicitly “prove” propositions. We can never prove an alternative hypothesis with 100% confidence. What we can do instead is reject the null hypothesis, supporting the alternative hypothesis.

It just so happens that it is easier to disprove a hypothesis than to positively prove one. But the supposition that the null hypothesis is incorrect allows for a stable foundation on which scientists can build. You can view it this way: the results from testing the null hypothesis lay the groundwork for the alternate hypothesis, which explores multiple ideas that may or may not be correct.

The alternative and null hypotheses are the two main types you’ll encounter in studies. But the alternative hypothesis can be further broken down into two categories: directional and nondirectional alternative hypotheses.

The directional alternative hypothesis predicts that the independent variable will have an effect on the dependent variable and the direction in which the change will take place. The nondirectional alternative hypothesis predicts the independent variable will have an effect but its direction is not specific, without stating the magnitude of the difference.

For instance, a non-directional hypothesis could be “there will be a difference in how many words children and adults can recall,” while the directional hypothesis could predict that “adults will recall more words than children.”

Hypotheses can be simple or complex. A simple hypothesis predicts a relationship between a single dependent variable and a single independent variable while a complex one predicts a relationship between two or more independent and dependent variables. An example of a complex hypothesis could be “Do age and weight affect the chances of getting diabetes and heart diseases?” There are two independent and two dependent variables in this statement whose relationship we seek to verify.

How to write a good hypothesis

The way you formulate a hypothesis can make or break your research because the validity of an experiment and its results rely heavily on a robust testable hypothesis. A good research hypothesis typically involves more effort than a simple guess or assumption.

Generally, a good hypothesis:

• is testable, meaning it must be possible to show that a hypothesis is true or false, and the results of this investigation have to be replicable;
• includes both an independent and dependent variable.
• allows for the manipulation of the variables ethically.
• has clear and focused language. Don’t be vague.
• is related to other published research.
• is written, either explicitly or not, as an “if-then” statement because we can then make a prediction of the outcome of an experiment.

An example of a testable good hypothesis is a conjecture such as “Students recall more information during the afternoon than during the morning.” The independent variable is the time of the lecture and the dependent variable is the recall of the information presented in the lecture, which can be verified with standardized tests.

A bad hypothesis could be something like “Goldfish make better pets than cats.” Right off the bat, you can see a couple of problems with this statement. What constitutes a good pet? Is a good pet fluffy and interactive or one that is low maintenance? Can I predict whether a cat or goldfish will make for a good pet? This is more a matter of opinion that doesn’t provide any meaningful results.

Often, the best hypotheses start from observation. For instance, everybody has witnessed that objects that are thrown into the air will fall toward the ground. Sir Isaac Newton formulated a hypothesis in the 17th-century that explains this observation, stating that ‘objects with mass attract each other through a gravitational field.’

But despite Newton’s hypothesis being very well written, in the sense that it is testable, simple, clear, and universal, we now know it was wrong. In the 20th-century, Albert Einstein showed that a hypothesis that more precisely explains the observed phenomenon is that ‘objects with mass cause space to bend.’ The lesson here is that all hypotheses are temporary and partial, they’re never permanent and irrefutable. This is also a good example of why the null hypothesis is so paramount.

Hypothesis formulation and testing through statistical methods are integral parts of the scientific method, the systematic approach to assessing whether a statement is true or false. All the best stories in science start with a good hypothesis. 

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Good Hypothesis Statement

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Every great scientific journey begins with a well-framed hypothesis. This predictive statement serves as the backbone of a study, guiding research thesis statement with precision and purpose. Whether you’re a budding researcher or a seasoned scientist, crafting a compelling hypothesis is paramount. This guide offers a curated selection of exemplary hypothesis statements, invaluable writing insights, and best practices to ensure your research sets sail on the right course. Dive in to fortify your foundational understanding.

What is a good hypothesis statement?

A good hypothesis statement is a clear, concise, testable, and falsifiable proposition that predicts a particular outcome or relationship between variables based on prior knowledge, observation, or reasoning. It serves as the foundation for the research, guiding the direction and focus of the study.

What is an example of a strong hypothesis?

Example: “Increased exposure to sunlight (independent variable) will lead to an elevation in Vitamin D levels (dependent variable) in adults.”

This simple hypothesis is strong because it’s specific, suggesting a clear relationship between the two variables. It’s also testable, as one can measure Vitamin D levels in adults with varying exposure to sunlight, and it’s falsifiable, as findings might reveal no significant change in Vitamin D levels despite changes in sunlight exposure.

100 Good Hypothesis Statement Examples

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Crafting an impeccable thesis statement is the bedrock of any research. It’s a concise Thesis statement summary of your main point or claim. Here, we present a variety of thesis statement examples across disciplines to inspire and guide your own writing endeavors.

• Climate Change: Human activities, primarily the burning of fossil fuels and deforestation, are the main drivers behind the alarming acceleration of global warming in the past century.
• Health and Diet: Regular consumption of fast food, due to its high salt and saturated fat content, is a significant contributor to heart diseases among adults.
• Social Media: Excessive use of social media platforms has led to increased rates of anxiety and depression among teenagers.
• Economics: The 2008 financial crisis was precipitated primarily by deregulation in the financial industry and rampant speculation in the housing market.
• Literature: Shakespeare’s “Macbeth” delves into the psychological repercussions of unchecked ambition, demonstrating its corrosive impact on one’s morality.
• Education: Incorporating hands-on learning in the curriculum enhances student engagement and promotes better understanding of academic concepts.
• Technology: The proliferation of smartphones has fundamentally transformed social interactions, leading to a decline in face-to-face communication skills.
• History: The fall of the Roman Empire was a culmination of external military pressure, internal political corruption, economic decline, and social unrest.
• Art: Renaissance art glorified human form and intellect, signifying a departure from the religious-centric art of the medieval period.
• Science: Quantum mechanics challenges traditional Newtonian physics principles, introducing the concept of superposition and quantum entanglement.
• Migration: The 20th-century Great Migration of African Americans from the rural South to the urban North was driven by the quest for better economic opportunities and escape from institutionalized racism.
• Culture: The global spread of K-pop is indicative of the universal appeal of musical elements coupled with strategic marketing.
• Psychology: Childhood traumas have long-lasting implications on adult mental health, often manifesting as anxiety, depression, or PTSD.
• Gender Studies: Glass ceiling effects persist in contemporary corporate structures, hindering women from attaining top leadership positions.
• Biology: Evolutionary processes, driven by natural selection, account for the diverse species observed in the natural world.
• Philosophy: Sartre’s existentialism posits that humans are condemned to be free, bearing the weight of shaping their essence through choices.
• Law: Mandatory minimum sentencing laws have not deterred drug offenses but have exacerbated the overpopulation issue in prisons.
• Religion: The Protestant Reformation in the 16th century was a reaction against clerical abuses and the question of salvation in the Catholic Church.
• Politics: The rise of populist movements in the 21st century can be attributed to increasing economic disparities and a sense of alienation from traditional political systems.
• Environment: The decline in bee populations is intricately tied to the extensive use of pesticides, posing significant threats to global agriculture.
• Film Studies: The “Star Wars” franchise revolutionized cinematic storytelling, introducing pioneering visual effects and a uniquely immersive universe.
• Medicine: The overprescription of antibiotics has led to the emergence of superbugs resistant to conventional treatments.
• Music: The Beatles’ influence in the 60s was instrumental in shifting the paradigms of songwriting and music production.
• Anthropology: The Indus Valley Civilization’s urban planning and architecture demonstrate advanced societal structures and knowledge bases.
• Sociology: The gig economy, spurred by technological advances, has both expanded opportunities for freelancers and intensified job insecurity.
• Astronomy: The existence of exoplanets in the Goldilocks zone suggests potential for life beyond our solar system.
• Architecture: Brutalist architecture, characterized by raw concrete and geometric designs, is a reflection of the post-war era’s emphasis on functionality over aesthetics.
• Criminal Justice: Racial profiling in policing perpetuates systemic racism, undermining trust in law enforcement agencies.
• Physics: Einstein’s theory of relativity fundamentally altered our understanding of time, space, and the universe’s fabric.
• Feminism: The #MeToo movement marked a significant turning point in highlighting and combating workplace sexual harassment.
• Geography: Urbanization trends in the 21st century have led to the growth of mega-cities, with associated challenges in sustainability and infrastructure.
• Ecology: The loss of biodiversity in rainforests due to deforestation has dire implications for global climate regulation and ecosystem balance.
• Journalism: The rise of digital journalism has democratized information dissemination but has also amplified the spread of misinformation.
• Linguistics: The Sapir-Whorf hypothesis suggests that the structure of a language shapes its speakers’ worldview and cognition.
• Sports: The commercialization of sports, driven by media rights and sponsorships, has both expanded its global reach and diluted its traditional ethos.
• Theatre: Brecht’s concept of “epic theatre” sought to provoke critical thinking in audiences, promoting a detachment from emotional immersion.
• Chemistry: The discovery of the DNA double helix by Watson and Crick unveiled the molecular basis of genetics and heredity.
• Ethics: Utilitarianism, which emphasizes the greatest good for the greatest number, often conflicts with individual rights and autonomy.
• Marketing: Consumer purchasing behaviors are increasingly influenced by social media influencers, marking a shift from traditional advertising methods.
• Fashion: The fashion industry’s fast fashion model contributes significantly to environmental degradation, emphasizing the need for sustainable practices.
• Marine Biology: Coral bleaching, exacerbated by climate change, threatens the health of marine ecosystems and the livelihood of coastal communities.
• Digital Humanities: The digitization of historical archives has enhanced accessibility but raises concerns about data integrity and preservation.
• Agriculture: Genetically modified organisms (GMOs) have improved crop yields but spark debates over health implications and biodiversity.
• Military Strategy: The doctrine of Mutually Assured Destruction during the Cold War deterred direct nuclear confrontation between superpowers.
• Urban Planning: Green spaces within urban areas not only enhance aesthetics but also significantly impact residents’ mental and physical well-being.
• Public Health: Vaccination campaigns have been instrumental in eradicating diseases like smallpox, underscoring the importance of global health cooperation.
• Neuroscience: Neuroplasticity challenges the belief that the adult brain is static, highlighting its adaptability and capacity for change post-injury.
• Political Science: Globalization, while fostering economic integration, has also exacerbated nationalist sentiments and identity politics.
• Psychiatry: Cognitive-behavioral therapy has emerged as an effective treatment for a range of mental disorders, emphasizing the interplay between thought and behavior.
• Pedagogy: Incorporating multiple intelligences in teaching strategies caters to diverse learning styles, promoting holistic education.
• Robotics: The integration of artificial intelligence in robotics has opened the door to more autonomous and adaptive machines, challenging traditional job roles.
• Literature: Shakespeare’s tragic heroes, like Hamlet and Othello, exemplify the struggle between personal desires and moral responsibilities.
• Economics: The gig economy, while offering flexibility to workers, often compromises long-term job security and benefits.
• Space Exploration: The Mars colonization idea, championed by private space companies, brings forth ethical, technological, and financial challenges.
• Medieval History: The Magna Carta, signed in 1215, laid the foundational principles for constitutional monarchies and the rule of law.
• Musicology: The transition from classical to romantic era in music signified an emphasis on emotion, individualism, and the sublime.
• Anthropology: The study of Neanderthal culture challenges long-held assumptions about their cognitive capabilities and societal structures.
• Social Media: The proliferation of social media has revolutionized global communication but also poses risks related to privacy and mental health.
• Genetics: The CRISPR technology holds promise for genetic editing but raises ethical dilemmas around altering the human genome.
• Migration Studies: The Syrian refugee crisis illuminated the global community’s challenges in addressing mass migrations due to conflict.
• Climate Science: The anthropogenic factors driving global warming necessitate an immediate shift towards sustainable energy sources.
• Art History: The Renaissance marked a rebirth in art and culture, characterized by a return to classical ideals and humanism.
• Endocrinology: The role of insulin in regulating blood sugar revolutionized the understanding and treatment of diabetes.
• Cinematography: The shift from film to digital cinematography has altered filmmaking aesthetics and production processes.
• Paleontology: The discovery of feathered dinosaur fossils bridged the evolutionary gap between reptiles and birds.
• Philosophy: Existentialism, rooted in the works of Sartre and Camus, delves into human freedom, responsibility, and the search for meaning.
• Data Science: The advent of big data analytics allows businesses to personalize customer experiences but grapples with data privacy issues.
• Forensic Science: DNA fingerprinting has revolutionized criminal investigations, enabling precise identification of suspects.
• Sociology: The concept of the “melting pot” in American society has evolved into the idea of a “salad bowl,” emphasizing multicultural coexistence.
• Dermatology: The understanding of the skin’s microbiome is reshaping treatments for dermatological conditions and overall skin health.
• Archeology: The deciphering of the Rosetta Stone paved the way for understanding ancient Egyptian civilization through hieroglyphics.
• Geology: The theory of plate tectonics provided a comprehensive explanation for earthquakes, volcanic activities, and continental drift.
• Astrophysics: The detection of gravitational waves confirmed Einstein’s prediction and opened a new observational window into the cosmos.
• Nutrition: The Mediterranean diet, rich in plant-based foods and healthy fats, has been linked to longevity and reduced risk of chronic diseases.
• Mycology: The study of mycorrhizal fungi demonstrates their essential role in plant nutrient uptake and ecosystem sustainability.
• Psychology: The study of neuroplasticity reveals that the human brain remains adaptable and can recover even after traumatic injuries, challenging previous beliefs about its rigidity.
• Oceanography: The deep-sea exploration has unveiled unique bioluminescent organisms, underscoring the ocean’s vast undiscovered biodiversity.
• Architecture: The Brutalist architectural movement, marked by raw concrete structures, challenges traditional notions of aesthetics while emphasizing functionality.
• Environmental Science: The introduction of the circular economy aims to reduce waste, highlighting the need for sustainable production and consumption patterns.
• Linguistics: The extinction rate of indigenous languages has accelerated, emphasizing the urgent need for preservation initiatives.
• Neuroscience: The discovery of mirror neurons sheds light on human empathy and our ability to understand others’ emotions and intentions.
• Cultural Studies: The globalization era has witnessed a blending of cultures, leading to hybrid cultural phenomena and redefining identities.
• Astronomy: The Kepler mission’s exoplanet discoveries have rekindled the age-old debate on the possibility of life beyond Earth.
• Zoology: The study of animal migration patterns is crucial in understanding the impacts of climate change on various species.
• Political Science: The rise of populist movements worldwide challenges traditional political paradigms and reflects widespread disillusionment with the establishment.
• Urban Studies: The concept of smart cities, integrating technology into urban planning, promises more sustainable and efficient urban centers.
• Agriculture: The promotion of permaculture practices can revolutionize modern farming by enhancing soil health and biodiversity.
• Biotechnology: The development of lab-grown meat offers potential solutions to the environmental and ethical concerns associated with traditional livestock farming.
• Quantum Physics: The double-slit experiment underscores the puzzling nature of quantum mechanics, challenging our understanding of reality.
• Digital Humanities: The digitization of historical manuscripts and artifacts democratizes access to knowledge and preserves cultural heritage.
• Ecology: The reintroduction of apex predators in ecosystems, like wolves in Yellowstone, demonstrates the intricate balance of food webs.
• Sport Science: The analysis of athletes’ biomechanics offers insights into optimal performance techniques and injury prevention.
• Meteorology: The study of atmospheric aerosols is vital in understanding their role in climate change and weather patterns.
• Folklore: The evolution of folk tales across cultures underscores the universality of human emotions and shared narratives.
• Nano-technology: The synthesis of graphene has revolutionized potential applications in electronics, energy storage, and even medical devices.
• Paleontology: The discovery of feathered dinosaur fossils in China challenges traditional understanding of avian evolution, hinting at a closer relationship between birds and some dinosaur species.
• Genetics: The mapping of the human genome has opened doors for personalized medicine, emphasizing the uniqueness of each individual’s genetic code.
• Ethnomusicology: The study of indigenous tribal music reveals deep-rooted cultural expressions and the universal human connection to rhythm and melody.
• Finance: The rise of decentralized finance (DeFi) platforms challenges the traditional banking system, emphasizing the potential of blockchain in revolutionizing finance.
• Anthropology: The study of ancient human migration patterns through DNA analysis has reshaped our understanding of early human civilizations and interactions.

Good Hypothesis Statement Examples for Research

A well-structured hypothesis for research statement  sets a clear path for investigation. It should be concise, specific, and testable based on available resources.

• Sociology: Single-parent households will experience higher stress levels than two-parent households.
• Environmental Science: Urban areas with more green spaces will have lower levels of air pollution.
• Education: Use of interactive e-learning tools will improve students’ understanding of complex concepts.
• Economics: Countries with higher literacy rates will showcase better economic growth.
• Political Science: Electoral participation will increase with more youth-focused political campaigns.
• Medicine: Regular aerobic exercise will reduce the risk of cardiovascular diseases.
• Psychology: Social media usage correlates positively with feelings of loneliness in young adults.
• Linguistics: Children exposed to multilingual environments will have superior cognitive flexibility.
• Anthropology: Indigenous tribes with minimal contact with modern civilization will have unique social structures.
• Astrophysics: Star systems with exoplanets in the habitable zone are more likely to contain signs of life.

Good Hypothesis Statement Examples for Science Fair

Crafting a solid hypothesis can make a science fair project stand out. It should be based on observable phenomena and be measurable.

• Botany: Plants watered with diluted coffee will grow faster than those watered with plain water.
• Chemistry: Adding salt will increase the boiling point of water.
• Physics: The elasticity of a rubber band will decrease as it is heated.
• Biology: Yeast fermentation will produce more CO2 in sugar solutions than in plain water.
• Earth Science: Crystals will grow faster in warmer solutions than in cooler ones.
• Ecology: Pond water will contain more microbial life than tap water.
• Astronomy: Urban areas will exhibit more light pollution, affecting star visibility.
• Environmental Science: Natural cleaners are as effective as chemical-based cleaners.
• Zoology: Ants prefer sugary solutions over salty ones.
• Microbiology: Hand sanitizers with a higher percentage of alcohol will kill more bacteria.

Good Hypothesis Statement Examples for Psychology

Hypotheses in psychology delve into human behavior, emotions, and cognition, aiming to predict outcomes based on conditions or stimuli.

• Cognitive: People who multitask are more prone to distractions.
• Developmental: Early exposure to musical instruments enhances spatial reasoning.
• Social: People with higher empathy levels are better at reading facial expressions.
• Clinical: Cognitive-behavioral therapy can effectively reduce symptoms of anxiety.
• Neuropsychology: Sleep deprivation will impair short-term memory.
• Evolutionary: Altruistic behaviors have evolved because they benefit the species.
• Health: Chronic stress can lead to lower immune responses.
• Forensic: Eye-witness testimonies can be influenced by leading questions.
• Sports: Athletes perform better under moderate levels of arousal.
• Educational: Incorporating visuals in teaching will improve retention rates in students.

Good Hypothesis Statement Examples in Biology

Biology hypothesis aim to predict the relationships between living organisms and their interactions with the environment.

• Genetics: Genetically modified crops will show higher resistance to pests.
• Ecology: Forest areas with diverse flora will support a wider range of fauna.
• Physiology: Mammals in colder regions will have thicker fur.
• Cell Biology: Cells exposed to toxins will show irregular mitosis.
• Marine Biology: Coral bleaching events correlate with rising ocean temperatures.
• Evolution: Birds with longer beaks are better adapted to access deep-seated food sources.
• Botany: Plants grown in acidic soil will show stunted growth.
• Zoology: Predatory animals in isolated islands will show gigantism.
• Microbiology: Bacteria exposed to antibiotics will develop resistance over generations.
• Neurobiology: Neurons exposed to neurotoxins will show reduced firing rates.

Good Hypothesis Statement Examples in Product Management

Hypotheses in product management help in predicting user behavior and guiding product enhancements.

• UX: Incorporating a chatbot will reduce the need for customer service intervention.
• Design: A minimalist design will improve user engagement and reduce bounce rates.
• Feature Set: Introducing a dark mode will increase user retention in a mobile app.
• Functionality: A more intuitive search feature will increase product sales on an e-commerce platform.
• Accessibility: Implementing voice commands will enhance usability for visually impaired users.
• Security: Two-factor authentication will reduce the likelihood of unauthorized account access.
• Integration: Synchronizing with popular social media platforms will increase user registrations.
• Performance: Improving load times will enhance user satisfaction scores.
• Feedback: Incorporating user feedback mechanisms will lead to more relevant feature releases.
• Compatibility: Ensuring multi-device compatibility will expand the user base.

Good Hypothesis Statement Examples for Digital Marketing

n digital marketing, a hypothesis can guide strategies by predicting how certain changes might influence online behavior.

• Content: Blog posts with more visuals will have higher user engagement.
• SEO: Mobile-optimized websites will rank higher in search engine results.
• Social Media: Posts published during peak user hours will receive more engagement.
• Email Marketing: Personalized email subject lines will have a higher open rate.
• PPC: Advertisements with emotional appeal will have a higher click-through rate.
• Affiliate Marketing: Products with higher user reviews will result in more affiliate sales.
• Influencer Marketing: Collaborations with micro-influencers will yield more organic engagement.
• Video Marketing: Videos with captions will have a longer view duration.
• Retargeting: Ads targeting cart abandoners will result in higher conversion rates.
• Analytics: Implementing heatmap tools will provide clearer insights into user behavior.

Good Testable Hypothesis Statement Examples

For a t estable hypothesis , it must present a potential scenario that can be proven right or wrong through experimentation or observational studies.

• Physics: Changing the angle of a ramp will alter the speed of a rolling object.
• Botany: Increasing the amount of sunlight exposure will affect the rate of photosynthesis in plants.
• Psychology: Children who play memory-based games will perform better in short-term memory tests.
• Chemistry: The rate of reaction will increase with a rise in temperature up to a certain point.
• Astronomy: The luminosity of a star is directly related to its mass.
• Meteorology: High humidity levels will increase the perception of temperature in humans.
• Geology: The age of a rock layer is inversely proportional to its depth in undisturbed strata.
• Physiology: The amount of REM sleep is related to memory consolidation in adults.
• Microbiology: Bacteria in unsanitized water will multiply faster at room temperature than in a cold environment.
• Nutrition: Consumption of Vitamin C will reduce the duration and severity of common cold symptoms.

Good Null Hypothesis Statement Examples

A null hypothesis assumes no relationship or effect between variables and serves as a foundation to be tested against an alternative hypothesis.

• Medicine: There is no difference in recovery rates between patients taking Drug A and those taking a placebo.
• Economics: The introduction of a new fiscal policy will have no effect on employment rates.
• Biology: There is no significant difference in growth rates between plants in shaded areas and those in sunlight.
• Sociology: Attending team-building workshops has no impact on employee productivity.
• Environmental Science: The presence of a new factory has no influence on local air quality measurements.
• Linguistics: Exposure to abooks has no impact on a child’s reading capability.
• Musicology: Learning a musical instrument has no influence on mathematical ability.
• Education: Using digital textbooks versus traditional textbooks has no effect on student comprehension.
• Psychology: Meditation practices have no effect on stress levels in college students.
• Sports Science: Consuming energy drinks has no effect on short-term athletic performance.

Effective Hypothesis Statement Examples

An effective hypothesis not only offers a testable proposition but also clarifies the scope and direction of the research, making the study’s intent transparent.

• Environmental Science: The proximity to urban centers impacts the biodiversity of freshwater streams.
• Neuroscience: Exposure to blue light before bedtime affects the quality of sleep in adults.
• Anthropology: Societies with matrilineal structures have different conflict resolution strategies compared to patrilineal ones.
• Pharmacology: Patients administered Drug B will show faster recovery rates from flu symptoms than those not administered any drug.
• Zoology: Predators introduced to an isolated ecosystem will alter the behavior patterns of local prey species.
• Archeology: Civilizations with access to river routes had more expansive trade networks.
• Literary Studies: Novels from post-war periods reflect societal trauma more than novels from peaceful times.
• Physics: The density of a material will affect its rate of thermal conduction.
• Marine Biology: Coral species in deeper waters are less susceptible to bleaching events.
• Political Science: Democracies with proportional representation voting systems have more diverse legislatures.

Can a hypothesis be a question?

Hypotheses and questions both originate from scientific curiosity. However, they serve distinct roles in research. A research question and hypothesis pinpoints what the researcher is trying to discover or understand. In contrast, a hypothesis is a formulated answer to that question based on prior knowledge, observations, or educated assumptions. It’s an informed prediction that is made to be tested. For example, upon asking “Does music affect concentration?”, a researcher might hypothesize, “Listening to classical music will improve concentration levels during tasks.” It’s essential to note that the question initiates the inquiry, while the hypothesis provides direction to the research.

What are the Characteristics of Good Hypothesis?

A strong hypothesis is not merely a guess. It’s constructed with thought, precision, and a foundation in existing knowledge:

• Empirical Foundation: This means the hypothesis can be tested and proven or disproven using systematic observations or experiments.
• Definitiveness: A clear, direct statement is more actionable. Avoid general or ambiguous statements.
• Alignment with Existing Knowledge: It’s essential that your hypothesis doesn’t clash with well-established scientific theories unless there’s a valid reason to challenge them.
• Feasibility: The hypothesis should be practical and testable using available resources.

Good Hypothesis vs Bad Hypothesis Examples

Good Hypothesis: “Eating dark chocolate in moderate amounts can improve mood in adults.” Why it’s good: The hypothesis provides specificity about the type of chocolate, quantity, the target group, and the outcome.

Bad Hypothesis: “Chocolate might change feelings.” Why it’s bad: This hypothesis is overly broad, lacking specifics on the type of chocolate, the demographic, or the nature of the change in feelings.

What is the Criteria of the Good Hypothesis?

Beyond being testable, a viable hypothesis should be:

• Relevant: Directly tackles the research query.
• Objectivity: Steer clear of personal biases or beliefs. Stick to what can be tested and observed.
• Generalizability: The findings from the hypothesis should ideally apply to scenarios beyond the immediate research context, amplifying its significance.

What are the 3 things a good hypothesis should have?

For a hypothesis to be effective:

• Scope: Set boundaries. Decide what is to be studied and under what conditions.
• Directionality: Your hypothesis should indicate whether one variable will increase or decrease in the presence of another.
• Clarity in Outcome: Predict a clear outcome based on the relationship between the variables.

How do you write a good hypothesis statement? – Step by Step Guide

Creating a hypothesis involves more than just making an educated guess:

• Frame the Inquiry: What is your central research question? What are you hoping to uncover?
• Literature Dive: Scour existing literature on the topic. This can be academic papers, books, or trusted online sources.
• Spot the Variables: What’s changing in your experiment? What are you observing?
• Draft It: Convert your insights into a concise, testable hypothesis.
• Avoid Absolutes: Science rarely deals in certainties. Your hypothesis should reflect the possibility of being disproven.
• Iterate: As you gather more data or insights, refine your hypothesis to better fit your findings.

Tips for Writing a Good Hypothesis Statement

Crafting a hypothesis is both an art and science:

• Prioritize Simplicity: Start simple, ensuring your hypothesis is straightforward and easy to understand.
• Be Open to Change: Research is about discovery, and as you uncover more, your initial hypothesis might need tweaking.
• Avoid Assumptions: Your hypothesis should be grounded in fact, not personal beliefs.
• Seek Peer Reviews: Share your hypothesis with colleagues or mentors. They might offer valuable feedback or insights you hadn’t considered.

In essence, a hypothesis is a guiding star in the vast sky of research. It provides direction, clarity, and purpose to your investigations, ensuring your efforts are targeted and meaningful.

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Writing Guides  /  How to Write a Hypothesis w/ Strong Examples

How to Write a Hypothesis w/ Strong Examples

A hypothesis is a guess about what’s going to happen.  In research, the hypothesis is what you the researcher expects the outcome of an experiment, a study, a test, or a program to be.  It is a belief based on the evidence you have before you, the reasoning of your mind, and what prior experience tells you.  The hypothesis is not 100% guaranteed—that’s why there are different kinds of hypotheses.  In this article, we’ll explain what those are when they should be used.  So let’s dive in!

What is a Hypothesis / Definition

A hypothesis is like a bet:  you size things up and tell your mates exactly what you think is going to happen with respect to X, Y, Z.  It can also be like an explanation for a phenomenon, or a logical prediction of a possible causal correlation among multiple factors. In science—or, really, in any field, a hypothesis is used as a basis for further investigation.  For example, many qualitative or exploratory studies are conducted just so that the researcher in the end can formulate a hypothesis after all the data is collected an analyzed.

In short, it is an educated guess, based on existing knowledge or observation.  It is a way of proposing a possible explanation for a relationship between variables.

One thing to remember is this:  the key characteristic of a hypothesis is that it must be testable and potentially falsifiable. This means that it should be possible to design an experiment or observation that could potentially prove the hypothesis wrong.  That is a very important point to keep in mind.

For that reason, hypotheses are usually only formulated after conducting a preliminary review of existing literature, observations, or after obtaining a general understanding of the subject area. They are not random guesses.  They are grounded in some form of evidence or understanding of the phenomena being studied. The formulation of a hypothesis is a big step in the scientific method, as it defines the focus and direction of the research.  A lot of time is often spent simply on developing a good hypothesis.

Why?  A well-constructed hypothesis not only proposes an explanation for an observation but also often predicts measurable and testable outcomes. It is not merely a question, but rather a statement that includes a clear explanation or prediction. For example, rather than asking “Does temperature affect the growth of bacteria?”, a hypothesis would be something like this:  “If the temperature increases, then the growth rate of bacteria will increase.”  It is clear, measurable, testable, and potentially falsifiable.

In the scientific community, a hypothesis is respected when it has the potential to advance knowledge, regardless of whether testing proves it to be true or false. The process of testing, refining, or nullifying hypotheses through experimentation and observation is part of what research is all about.

 Different types of Hypotheses

Hypotheses can be categorized into several types.  Each type has a unique purpose in scientific research.  Understanding these types is helpful for formulating a hypothesis that is appropriate to your specific research question. The main types of hypotheses include the following:

• Simple Hypothesis : This formulates a relationship between two variables, one independent and one dependent. It is straightforward and concise, making it easy to test.  It is most often used in basic scientific experiments where the aim is to investigate the relationship between two variables, such as in laboratory experiments or controlled field studies.
• Complex Hypothesis : Unlike the simple hypothesis, a complex hypothesis involves multiple independent and dependent variables. It is used in studies that are looking at several factors simultaneously, where there is an interplay of multiple variables. These are common in fields like social sciences, behavioral studies, and large-scale environmental research.
• Directional Hypothesis : This type predicts the nature of the effect of the independent variable on the dependent variable. It specifies the direction of the expected relationship.  It tends to be used studies where prior research or theory has already suggested a specific direction of influence or effect, such as in clinical trials or in studies testing theoretical models.
• Non-directional Hypothesis : In contrast to the directional hypothesis, a non-directional hypothesis does not specify the direction of the relationship. It simply suggests that there is a relationship between variables without stating whether it is positive or negative.  It is often used in exploratory research where the direction of the relationship is not known, such as in early-stage psychological research or when studying new phenomena.
• Null Hypothesis : The null hypothesis states that there is no relationship between the variables being studied. It is a default position that assumes no effect until evidence suggests otherwise.  It is also a fundamental aspect of virtually all quantitative research, serving as the hypothesis that there is no effect or no difference, against which the alternative hypothesis is tested.
• Associative and Causal Hypotheses : Associative hypotheses propose a relationship between variables where changes in one variable correspond with changes in another.  They are common in observational studies, such as epidemiological research or surveys, where the goal is to identify correlations between variables.  Causal hypotheses go a step further by suggesting that one variable causes the change in the other.  They are used in experimental research designed to determine cause-and-effect relationships, such as randomized controlled trials in medical research or controlled experiments in psychology.

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How to Write a Good Hypothesis

Writing a good hypothesis is definitely a good skill to have in scientific research. But it is also one that you can definitely learn with some practice if you don’t already have it.  Just keep in mind that the hypothesis is what sets the stage for the entire investigation.  It guides the methods and analysis.  Everything you do in research stems from your research question and hypothesis.

Here are four essential steps to follow when crafting a hypothesis:

• Start with a Research Question

Every hypothesis begins with a clear, focused research question. This question should arise from a review of existing literature, some observations you have made in the field, or an information gap that is apparent in current knowledge. The question should be specific and researchable.  For example, instead of a broad question like “What affects plant growth?”, a more specific question would be “How does the amount of water affect the growth of sunflowers?”  This is a specific question, and sets up a stage for a perfect hypothesis.

How did you develop the question?  Easy.  You simply took a broad view first, and then began looking more closely.  You looked into the subject matter.  And, as with anything, the more you look into it, the more likely you are to have questions.  So, the most important step here is to get a sense of your subject.  The more you learn about it, the more likely you will be to have a good research question.  Ask yourself:  what about this subject would I like to know more about?  It helps if you have a genuine interest in the topic!  Say, for example, you want to know more about cryptocurrency security or scalability:  wouldn’t you start asking questions about how to achieve either?  And wouldn’t you need to know a bit about the topic before you can ask the right question?  Of course!  Apply that same logic to whatever subject you are researching and your research question will appear rather quickly.

• Do Preliminary Research

Before formulating your hypothesis, you of course should conduct preliminary research. This involves reviewing existing literature, understanding the current state of knowledge in the field, doing some critical thinking on the subject, and considering any existing theories and findings that might be relevant. This preliminary research helps in developing an educated guess.  If you do your background research well, your hypothesis will be grounded in existing knowledge.

This is basically the step that comes after you ask your research question but before you make a prediction about the subject matter.  Just like if you went to a racetrack and wanted to place a bet on a horse, you would research the horses, the owners, the teams, and make an educated guess about which one is most likely to win, doing preliminary research is the same:  you want to become very familiar with the topic—know it inside and out.  Then you will have everything you need to formulate your hypothesis.

• Formulate the Hypothesis

Based on your research question and preliminary research, now you can create your hypothesis. A good hypothesis should be clear, concise, and testable. It typically takes a statement form, predicting a potential outcome or relationship between variables. Make sure that your hypothesis is focused and answers your research question.  For example, a hypothesis for the research question stated above might be:   “If sunflower plants are watered with varying amounts of water, then those watered more frequently will grow taller due to better hydration.”

Keep in mind that when you reach the stage of formulating your hypothesis, you are essentially ready to make a statement that can be tested through research or experimentation. Your hypothesis should be as precise as possible. Don’t ever use ambiguous language in your hypothesis.  Also, you should be very specific about the variables involved and the expected relationship between them (if applicable).  For example, let’s look at the hypothesis we generated above:  “If sunflower plants are watered with varying amounts of water, then those watered more frequently will grow taller due to better hydration.”  We have clearly identified the variables (frequency of watering and plant growth height) and the expected outcome.

But what else should your hypothesis do?  Well, when we say it should address your research question, we mean it should be a logical extension of the question and your preliminary research.  If your research question is about the effect of watering frequency on sunflower growth, your hypothesis should specifically predict how these two variables are related.  It should not get into the types of soil, sunshine, temperature, or other variables unless these were brought up specifically in your research question.

Above all, you want your hypothesis to make a prediction. This means stating an expected outcome based on your understanding of the subject. The prediction is what will be tested through experiments or observations.

• Ensure Testability and Falsifiability

An important aspect of a good hypothesis is that it must be testable and potentially falsifiable. This means you should be able to conduct experiments or make observations that can support or refute the hypothesis. Avoid vague or broad statements that cannot be empirically tested.  Also, make sure that your hypothesis is potentially falsifiable; i.e., there should exist the possibility that it can be proven wrong.  For example, a hypothesis like “Sunflower plants need water to grow” is not falsifiable, as it is already a well-established fact.  But a hypothesis regarding frequency or amount of watering does have the potential to be nullified.

Therefore, keep that in mind during this step:  for a hypothesis to be testable, there must be a way to conduct an experiment or make observations that can confirm or disprove it. This means you should be able to measure or observe the variables involved. In the sunflower example, you can measure plant growth and control the frequency of watering very easily.  This is precisely what makes the hypothesis testable.

Another important point is falsifiability, as this is what separates scientific hypotheses from non-scientific ones.  If it doesn’t have the potential to be proven wrong, it’s not a hypothesis.  Being falsifiable doesn’t mean a hypothesis is false. It means that if the hypothesis is false, there is a way to demonstrate this. The potential for falsification is what allows researchers to make scientific progress no matter the problem or field.

Also, don’t be vague.  Your hypothesis needs to be specific: hypotheses that are too vague or broad are not useful in research, as there is no way to test them.  For example, saying “Water affects plant growth” is too vague.  How does water affect growth?  Is it the amount, frequency, or type of water?  Such a hypothesis needs to be more specific to be testable.  See what we mean?

Remember:   A hypothesis does not need to be correct.  It just needs to be testable.  It is a starting point for investigation. The value of a hypothesis lies in its ability to be tested.  The results of that test are what can potentially contribute to the existing body of scientific knowledge, regardless of whether the hypothesis is supported or refuted by the resulting data.

Hypothesis Examples

Simple hypothesis examples.

• Increasing the amount of natural light in a classroom will improve students’ test scores.
• Drinking at least eight glasses of water a day reduces the frequency of headaches in adults.
• Plant growth is faster when the plant is exposed to music for at least one hour per day.

Complex Hypothesis Examples

• Students’ academic performance is influenced by their study habits, family income, and the educational level of their parents.
• Employee productivity is affected by workplace environment, job satisfaction, and the level of personal stress the worker encounters both on the job and at home.
• The effectiveness of a weight loss program is dependent on the participant’s age, gender, and adherence to an appropriate diet plan.

Directional Hypothesis Examples

• Exposure to high levels of air pollution during pregnancy will increase the risk of asthma in children.
• A diet high in antioxidants will decrease the risk of heart disease in middle-aged adults.
• Regular physical exercise leads to a significant decrease in the symptoms of depression in adults.

Non-directional Hypothesis Examples

• There is a relationship between the amount of sleep a person gets and their level of stress.
• A change in classroom environment has an effect on student concentration.
• The introduction of ergonomics in the workplace environment impacts employee productivity.

Null Hypothesis Examples

• There is no significant difference in test scores between students who study in groups and those who study alone.
• Dietary changes have no effect on the improvement of symptoms in patients with type 2 diabetes.
• The new marketing strategy does not affect the sales numbers of the product.

Associative Hypothesis Examples

• There is an association between the number of hours spent on social media and the level of anxiety in teenagers.
• Daily consumption of green tea is associated with weight loss in adults.
• The frequency of public transport use correlates with the level of urban air pollution.

Causal Hypotheses Examples

• Implementing a school-based exercise program causes a reduction in obesity rates among children.
• High levels of job stress cause an increase in blood pressure.
• Smoking causes an increase in the risk of developing lung cancer.

In conclusion, understanding and effectively formulating a solid hypothesis is what scientific research and inquiry is all about—regardless of the type of work you’re doing.  It may be a simple, complex, directional, non-directional, null, associative, or causal hypothesis—no matter:  each type has its own specific purpose and guides the direction of a study in a different way. A simple hypothesis explores the relationship between two variables, while a complex hypothesis involves multiple variables. Directional hypotheses specify the expected direction of a relationship, whereas non-directional hypotheses do not. The null hypothesis, a fundamental aspect of statistical testing, posits no effect or relationship, serving as a baseline for analysis. Associative hypotheses explore correlations between variables, and causal hypotheses aim to establish cause-and-effect relationships.

The ability to craft a clear, concise, and testable hypothesis is important for any researcher. It is what shapes the course of the investigation.  It is also the backbone of the scientific method itself. A well-formulated hypothesis can lead to groundbreaking research or make significant contributions to knowledge in different fields.

As we have shown you with our examples, the hypothesis is more than a mere guess; it is an educated, testable prediction that guides you through the process of scientific discovery. When you master the art of hypothesis formulation, you can set off on your investigation with a clear roadmap and a clear sense of purpose.

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