After figuring out what you want to study, what is the next step in designing a research experiment? You, the researcher, write a hypothesis and null hypothesis. This lesson explores the process and terminology used in writing a hypothesis and null hypothesis.
After determining a specific area of study, writing a hypothesis and a null hypothesis is the second step in the experimental design process. But before you start writing a hypothesis and a null hypothesis, which we will get to, you have to have a question. This is the bottom, or base, which you will build up from.
What are you interested in? What are you curious about? This is a good place to start because your research should answer the question. I am curious about the effects of bright lights on studying. You take the thing you are interested in and turn it into a question. Here is mine: 'What is the effect of bright light on studying?' That's how easy it is to write a research question. Next we will explore how to formulate a research hypothesis based on your research question, then we'll look into what a null hypothesis is and how to write one of these.
Formulating a Hypothesis
You have a question and now you need to turn it into a hypothesis. A hypothesis is an educated prediction that provides an explanation for an observed event. An observed event is a measurable result or condition. If you can't measure it, then you can't form a hypothesis about it because you can't confirm or reject it. In addition, a hypothesis typically takes the form of an if-then statement so you can test it with your research. What does our hypothesis look like?
'If we increase the amount of light during studying, then the participant's performance on test scores will decrease.'
Let's break down our hypothesis. First off, it is an if-then statement: 'If we increase..., then the participant's...' This creates a prediction that we can test by increasing the light on participants as they study and then see if their test scores go down. It also means that the hypothesis can be proven correct or incorrect based on what happens to the test scores. If test scores don't change, then our hypothesis was incorrect and we will reject it.
You probably also noticed that we changed 'studying' to 'test scores' and the vague term about 'bright light' into 'amount of light.' This is an example of operationalizing, which is finding a way to measure or quantify a variable. Studying can't really be researched, but test scores can. And they are basically the same thing since studying typically increases test scores. Also, simply saying 'light' is too vague to be useful or researched, so it was turned into 'amount of light.'
After you formulated your research hypothesis, what if there isn't a connection between light and studying? That is kind of what a null hypothesis is; a null hypothesis is defined as a prediction that there will be no effect observed during the study. The reason researchers develop a null hypothesis is to ensure that their research can be proven false. So whenever you are conducting an experiment with a hypothesis, you will create a null hypothesis. Research typically includes a hypothesis, and when this is the case you will form a null hypothesis as a counterbalance to ensure there is a way to disprove your prediction.
A null hypothesis is the prediction a researcher hopes to prove false. The null hypothesis for our study would be: 'There will be no difference in test scores between the different amounts of light.' The focus of our null hypothesis is on what we are studying: the tests. When we write our null hypothesis, we are expecting the focus of our study, the test scores, to be unaffected by what we are manipulating: the light levels. The null hypothesis doesn't need to be an if-then statement. It basically says nothing is going to happen in our experiment or that there is no connection between the different parts of the hypothesis.
A hypothesis that cannot be proven false isn't really science; it's pseudoscience, and it brings the whole scientific field of psychology down. In our light and studying experiment, let's say we made the following prediction: 'Students will perform better unless they unconsciously notice the changes in light.' How do we demonstrate what a student notices unconsciously? The answer is you can't. What this prediction is cannot be proven wrong.
So one of the most important aspects of a hypothesis is that it can be demonstrated to be accurate or inaccurate. When you create a hypothesis like the one we just spoke of, about the students unconsciously noticing light changes, you may have moved from the scientific field of psychology to the realm of philosophy since there is basically no way to demonstrate unconscious thoughts. Your hypothesis must have a null hypothesis to be scientific.
When formulating a research hypothesis, you have to start with a research question. Next, you turn the question into a hypothesis, which is an educated prediction that provides an explanation for an observed event. After you have a hypothesis, you develop a null hypothesis, defined as a hypothesis that there is no effect.
After finishing this lesson, you should be able to:
- Compare and contrast hypothesis, null hypothesis and invalid hypothesis
- Discuss the process of formulating a hypothesis
- Understand the significance of the research question and the 'if/then' statement