Content

• To step
• Part 1 of 2: Preparing to write a hypothesis
• Part 2 of 2: Formulating the hypothesis
• Tips

A hypothesis is a description of a pattern in nature or an explanation of some real-life phenomenon that can be tested through observation or experimentation. The most common use of a hypothesis in scientific research is as a preliminary, testable, and refutable statement explaining a phenomenon observed in nature. More specifically, we call such a statement one explanatory hypothesis. However, a hypothesis can also be a statement describing an observed pattern in nature. In this case, we call the statement one generalizing hypothesis. Hypotheses can predictions generate: statements that state that a variable will have a certain result (effect or change) in a controlled experiment. However, many scientific sources fuel the myth that a hypothesis is nothing more than one well-founded estimate and not very different from a prediction. More about this misunderstanding below. Many academic fields, from the physical sciences to the social sciences, use hypotheses as a means of testing ideas, learning more about the world and increasing scientific knowledge. Whether you are a beginning teacher or a university student, it is very important to understand and be able to formulate hypotheses and predictions yourself. These instructions will help you on your way.

To step

Part 1 of 2: Preparing to write a hypothesis

1. Select a subject. Choose a topic that interests you and you want to learn more about.
   • If you are writing a hypothesis for school, this step may have already been done for you.
2. Read existing research. Gather all the information you can about the topic you selected. You need to become an expert on the topic and develop a solid understanding of what is known about the topic.
   • Focus on academic and scientific sources. You want to make sure that your information is impartial, accurate and complete.
   • Information can be found in textbooks, a library or online. At school, you can also ask for help from teachers, librarians, and fellow students.
3. Analyze the literature. Spend some time reading the materials you have collected. As you do this, look for unanswered questions in the literature and make a note of them. These provide excellent ideas for areas to investigate.
   • For example, if you are interested in the effects of caffeine on the human body, but find that no one seems to have explored the differences between men and women, this is something to hypothesize about. Or if you are interested in organic farming, you may find that no one has tested whether organic fertilizer results in different growth rates for plants compared to fertilizers.
   • You can sometimes find gaps in the existing literature by looking for statements such as "it is unknown" or places where information is clearly lacking. You may also find a claim in the literature that seems far-fetched, unlikely, or too good to be true, such as that caffeine would improve math skills. If the claim can be tested, then you can do science a great service by doing your own research. If you can confirm the claim, then the claim becomes even more credible. If you cannot find support for the claim, then you are contributing to the self-correcting aspect of science.
   • Researching these types of questions provides an excellent way to differentiate yourself by filling in important gaps in an area of ​​study.
4. Make up questions. After studying the literature on your topic, come up with one or more unanswered questions that you want to explore further. These are your research questions.
   • Following the examples above, you may ask yourself, "How does caffeine affect women compared to men?" or "What is the influence of organic fertilizer on plant growth, compared to fertilizers?" The rest of your research will then focus on answering these questions.
5. Look for clues as to what the answer might be. After you've generated one or more research questions, look in the literature to see if existing findings and / or theories on the topic provide any clues to come up with ideas about what the answers to your research questions might be. If so, these clues can form the basis for your hypothesis.
   • If, according to the above examples, you discover in the literature that there is a pattern showing that some other types of stimulants seem to be more effective in women than in men, this may indicate that the same pattern is also true for caffeine. Likewise, if you find that organic fertilizer generally appears to be related to smaller plants, you could explain this pattern by hypothesizing that plants exposed to organic fertilizer grow more slowly than plants exposed to fertilizers.

Part 2 of 2: Formulating the hypothesis

1. Determine your variables. a generalizing hypothesis describes a pattern that you think exists between two variables: an independent and a dependent variable. If your experiments confirm the pattern, you can formulate a reason why the pattern exists, or a mechanism that generates the pattern. The reason, or mechanism you propose, is called a explanatory hypothesis.
   • You can think of the independent variable as the cause of some kind of difference or effect. In the examples, the independent variable can be gender, whether a person is male or female, or the type of fertilizer (i.e., whether the fertilizer is organic or artificial).
   • The dependent variable is that which is affected by (that is, "depends on") the independent variable. In the examples above, the dependent variable could be the measured effect of caffeine or fertilizer.
   • Your hypothesis should only suggest one relationship. Above all, there should be only one independent variable. If you have more than one, you can no longer determine which one is actually the source of any effects you might observe.
2. Create a simple hypothesis. Once you've spent some time thinking about your research question and the variables, write down your initial idea of ​​how the variables relate to each other as a simple declaration.
   • Don't worry about accuracy or detail at this point.
   • In the examples above, one hypothesis may explain whether a person's gender can affect how the person is affected by caffeine; for example, at this point your hypothesis might be, "A person's biological sex is related to how caffeine affects his or her heart rate." The other hypothesis could be a general statement about plant growth and fertilizer; your simple explanatory hypothesis could be something like, "Plants given different fertilizers are different in size because they grow at different rates."
3. Decide on your direction. Hypotheses can be directional or non-directional. A non-directional hypothesis simply states that one variable affects the other in some way, but not specifically in what way. A directional hypothesis provides more information about the type (or "direction" of the) relationship, specifically stating how one variable affects another.
   • Using our example, our non-directional hypothesis could be something like, "There is a relationship between a person's biological sex and the degree to which caffeine increases the person's heart rate," and "There is a relationship between the type of fertilizer and the rate. with which plants grow. "
   • Directional predictions using the same sample hypotheses as above, could be something like, "Women will experience a stronger increase in heart rate after consuming caffeine than men," and "Plants fertilized with inorganic fertilizer will grow faster than those fertilized with organic fertilizer. " Indeed, these predictions and the hypotheses that make them possible are very different types of explanations. More about this distinction below.
   • If the literature allows for making a directional prediction, then it is better to do this because it provides more information. Especially within the natural sciences, non-directional predictions are often seen as inadequate.
4. Be specific. Once you have a first idea on paper, it's time to start refining. are you making hypotheses as specific as possible, so that it is clear exactly which ideas you are going to test and create predictions more specific and measurable, so that they prove a relationship between the variables.
   • Where appropriate, specify the population (i.e. the people or things) where you hope to discover more new knowledge. For example, if you're only interested in the effects of caffeine on older people, your prediction might be, "Women over 65 will experience a greater increase in heart rate than men of the same age." If you are only interested in the influence of fertilizers on tomato plants, your prediction could be: "Tomato plants treated with fertilizer will grow faster in the first three months than tomato plants treated with organic fertilizer."
5. Make sure it is testable. Make sure that the hypothesis you propose about a relationship between two variables, or a reason why a relationship exists between two variables, can be reasonably observed and measured in the real and observable world.
   • For example, a hypothesis such as "red is the prettiest color" is not really helpful. This statement is an opinion and cannot be tested by experiment. However, the generalizing hypothesis that red is the most popular color can be tested with a simple random survey. If you can indeed confirm that red is the most popular color, then your next step might be to ask: Why is red the most popular color? The answer you propose is you explanatory hypothesis.
   • Hypotheses are often made in the form of if-then sentences. For example, "if kids are on caffeine, their heart rate will increase." This statement is not a hypothesis. These kinds of explanations are a brief description of an experimental method followed by a prediction and are the most common misuse of hypotheses in science education. An easy way to formulate a hypothesis and prediction with this method is to ask yourself why you think the heart rate of children who are given caffeine will increase. You explanatory hypothesis in this case may be that caffeine is a stimulant. At this point, some scientists write a so-called research hypothesis, a statement in which the hypothesis, experiment, and prediction are all in one statement: If caffeine is a stimulant and some children are given a drink with caffeine in it while others are given a drink without caffeine, the heart rate of the children who received the drink with caffeine will increase more than the heart rate of the children who received the drink without caffeine. .
   • It may sound strange, but researchers rarely prove that a hypothesis is correct or incorrect. Instead, they look for evidence that the opposite of their hypotheses is unlikely to be true. If the opposite (caffeine is not a stimulant) is likely not true, then the hypothesis (caffeine is a stimulant) will likely be true.
   • Using the example above, we can say that if you test the effects of caffeine on the heart rate of children, evidence that the hypothesis is not true (also called the null hypothesis), may occur if the heart rates of the children who received the caffeinated drink and the children who did not receive the caffeinated drink (the placebo control) have not been changed, decreased, or increased by the same size, and if there was no difference between the two groups of children.If you wanted to test the effects of different fertilizers, proof that the hypothesis is not true could be that the plants grow at the same rate regardless of the fertilizer or that plants treated with organic fertilizers grow faster. It's important to note here that the null hypothesis actually becomes much more useful when researchers test the meaning of their results with statistics. When statistics are used in the results of an experiment, a researcher tests the idea of ​​the null statistical hypothesis. For example, that there is no relationship between two variables or there is no difference between two groups.
6. Test your hypothesis. Make your observations or conduct your experiment. Your proof may allow you to reject the null hypothesis, thus substantiating your experimental hypothesis. But the evidence may not allow you to reject the null hypothesis, and that's okay. Every result is important, even when your result sends you back to the drawing board. Constantly going back to "the drawing board" to refine your ideas is how science really works!

Tips

• During your literature search, do studies that are similar to what you want to do, and try to work on the findings of other researchers. But also pay attention to allegations that you find suspicious and test them yourself.
• Be specific in your hypotheses, but not so specific that the hypothesis cannot be applied to anything outside of your particular experiment. You want to be absolutely clear about the population you want to draw conclusions about, but no one (except your roommates) will be interested in reading a paper predicting, “My three roommates will each be able to do a different number of push-ups. "
• Keep your feelings and opinions out of your research. Hypotheses should never state something like, "I believe ...", "I think ...," "I feel ..." or "my advice is that ..."
• Remember that science is not necessarily a linear process and can be approached in different ways.