A hypothesis is an important part of the scientific method. It’s an idea or a proposal based on limited evidence. What comes next is the exciting part. The idea or proposal must be proven through facts, direct testing and evidence. Since the hypothesis acts as the foundation for future research, learn how to write a hypothesis through steps and examples.
A hypothesis statement tells the world what you predict will happen in research. One of the most important elements of a hypothesis is that it must be able to be tested. Sure, you might hypothesize that unicorn horns are made of white gold. But, if you can’t test the independent and dependent variables, your hypothesis will have to remain in your dreams.
If, however, you hypothesize that rose quartz and other crystals possess healing powers, then you might be able to perform a few tests and carry on with your hypothesis. You will have some evidence that either supports or does not support your hypothesis. Now that you know what it is, it’s time to learn how to write a hypothesis.
When it comes to writing a hypothesis, there are six basic steps:
- Ask a question.
- Gather preliminary research.
- Formulate an answer.
- Write a hypothesis.
- Refine your hypothesis.
- Create a null hypothesis.
In the scientific method, the first step is to ask a question. Frame this question using the classic six: who, what, where, when, why, or how. Sample questions might include:
- How long does it take carrots to grow?
- Why does the sky get darker earlier in winter?
- What happened to the dinosaurs?
- How did we evolve from monkeys?
- Why are students antsier on Friday afternoon?
- How does sleep affect motivation?
- Why do IEP accommodations work in schools?
You want the question to be specific and focused. It also needs to be researchable, of course. Once you know you can research your question from several angles, it’s time to start some preliminary research.
Remember, it’s important to explore your question from all sides. Don’t let conflicting research deter you. You might come upon many naysayers as you gather background information. That doesn’t invalidate your hypothesis. In fact, you can use their findings as potential rebuttals and frame your study in such a way as to address these concerns.
For example, if you are looking at the question: "How does sleep affect motivation?", you might find studies with conflicting research about eight hours vs. six hours of sleep. You can use these conflicting points to help to guide the creation of your hypothesis.
After completing all your research, think about how you will answer your question and defend your position. For example, say the question you posed was:
How does sleep affect motivation?
As you start to collect basic observations and information, you'll find that a lack of sleep creates a negative impact on learning. It decreases thought processes and makes it harder to learn anything new. Therefore, when you are tired, it's harder to learn and requires more effort. Since it is harder, you can be less motivated to do it. Additionally, you discover that there is a point where sleep affects functioning. You use this research to answer your question.
Getting less than eight hours of sleep makes it harder to learn anything new and make new memories. This makes learning harder so you are less likely to be motivated.
With the answer to your question at the ready, it’s time to formulate your hypothesis. To write a good hypothesis, it should include:
- Relevant variables
- Predicted outcome
- Who/what is being studied
Remember that your hypothesis needs to be a statement, not a question. It’s an idea, proposal or prediction. For example, a research hypothesis is formatted in an if/then statement:
If a person gets less than eight hours of sleep, then they will be less motivated at work or school.
This statement shows you:
- who is being studied - a person
- the variables - sleep and motivation
- your prediction - less sleep means less motivation
While you might be able to stop at writing your research hypothesis, some hypotheses might be a correlation study or studying the difference between two groups. In these instances, you want to state the relationship or difference you expect to find.
A correlation hypothesis might be:
Getting less than eight hours of sleep has a negative impact on work or school motivation.
A hypothesis showing difference might be:
Those with seven or fewer hours of sleep are less motivated than those with eight or more to complete tasks.
Depending on your study, you may need to perform some statistical analysis on the data you collect. When forming your hypothesis statement using the scientific method, it’s important to know the difference between a null hypothesis vs. the alternative hypothesis, and how to create a null hypothesis.
- A null hypothesis, often denoted as H0, posits that there is no apparent difference or that there is no evidence to support a difference. Using the motivation example above, the null hypothesis would be that sleep hours have no effect on motivation.
- An alternative hypothesis, often denoted as H1, states that there is a statistically significant difference, or there is evidence to support such a difference. Going back to the same carrot example, the alternative hypothesis is that a person getting six hours of sleep has less motivation than someone getting eight hours of sleep.
Here are a few examples of good and bad hypotheses to get you started.
How long does it take carrots to grow?
Good: If we plant carrots deep in the soil, it will take them longer to grow than in shallow soil.
Bad: You can plant carrots deep in the soil. (There’s no predicted outcome.)
Why does the sky get darker earlier in winter?
Good: The Earth's rotation affects the number of daylight hours.
Bad: The sun goes down. (This doesn’t clarify variables or what will be studied.)
What happened to the dinosaurs?
Good: If we study marine fossils found in the Arctic, we will see that dinosaurs disappeared when a comet hit the Earth.
Bad: Extinction happened thousands of years ago. (This does not name what is being studied nor present clear variables for studying dinosaur history.)
How did we evolve from monkeys?
Good: Human beings are not descended from apes, but share a common ancestor with them.
Bad: Human evolution is long. (This does not present clear variables to be studied or a prediction to be tested.)
|Why are students antsier on Friday afternoon?|
Good: Students are anticipating the coming of the weekend, making them antsier on Friday afternoon.
Bad: Students have bad behavior. (This isn't showing what is being tested or clear variables.)
|How does sleep affect motivation?|
Good: If a person gets less than eight hours of sleep, then they will be less motivated at work or school.
Bad: Sleep is important. (While this might be true, it's not setting the variables for the study.)
|Why do IEP accommodations work in schools?|
Good: If a student gets accommodations for their learning disability, then they will perform better in school.
Bad: Accommodations help students. (Again, while this might be true, it's not providing what is being studied or the variables.)
To write a strong hypothesis, keep these important tips in mind.
- Don’t just choose a topic randomly. Find something that interests you.
- Keep it clear and to the point.
- Use your research to guide you.
- Always clearly define your variables.
- Write it as an if-then statement. If this, then that is the expected outcome.
A hypothesis involves a statement about what you will do, but also what you expect to happen or speculation about what could occur. Once you’ve written your hypothesis, you’ll need to test it, analyze the data and form your conclusion. To read more about hypothesis testing, explore good examples of hypothesis testing.