Science Fair Experiment

Time for your science fair experiment. You’ve got an idea; you’ve picked your topic, done your research and now you are ready. Great! Let’s outline the experimental process:

  1. Question
  2. Hypothesis
  3. Test of Hypothesis
  4. Gather Data
  5. Conclusion and Report

If you looked at the scientific method on the Ideas page, this will look familiar to you. That’s no coincidence; this experimental process outline is just another view of the scientific method.

On this page, we are going to cover the first three of these steps. 


In order to do an experiment, you need to have a science fair questionthat you are trying to answer.

When you have a question in mind, you will want to identify anIndependent Variable, your Dependent Variable(s), and your Controlled Variables. This is a very important step in order to make your science fair experiment valid.

Put simply: Pick a some interesting aspect of your topic and choose a question about that which you can answer by doing a science fair experiment.

When doing your experiment it will be very important for you to identify any Controlled Variables that might affect the outcome of your experiment.

Got your question? Great, let’s go on. 


Now that you have a question about an interesting topic which you’ve researched, it's time to create your science project hypothesis. 

If you can’t come up with a hypothesis that seems right, go back and try reworking your question. If you can’t seem to come up with a good hypothesis, it’s probably because the question is not specific enough. Don’t give up! It may take a few minutes to come up with a good Question/Hypothesis combination that works.

At this point, you can still make major changes to your science fair experiment and not waste a lot of time. So if you are unhappy with your question or hypothesis for any reason then now is a great time to come up with something better that does please you.

Once you begin the actual process of experimentation, changing your mind can cost you a lot of time or money or both. So be doubly sure you are ready before proceeding. 

Test of Hypothesis

Now that you have your question and a hypothesis you can do a hypothesis test. When you do the test you are testing to see if your hypothesis, your guess about what will happen, was correct.

Your guess maybe right or it may be wrong. Whether it is correct or not is not of the utmost importance - the most important thing is to follow the scientific method and perform your experimentation correctly! If you do, you will get valuable scientific information to present even if your hypothesis turns out to be incorrect.

It is advisable to setup your experiment so that you can run your science project hypothesis test multiple times in order to check your work. If you get similar results each time, it is likely that your experiment is valid. 

Am I Done?

If you are done, the next step involves gathering your data, drawing conclusions and reporting your results. If you are still unsure and would like a few examples to get started then have a look at these to get a better idea of what kind of science fair experiment you would like to do.

Here is a simple to test for yourself in order to figure out if you have a good procedure for your science fair experiment: could you give all of your notes about how to do the experiment to a friend and expect them to be able to duplicate your test results without talking to you about it? If the answer is “yes!” then you have covered all the angles of your experiment well.

So, you have done your experimentation, and recorded your results – now it’s time to gather your data.