Design your science fair experiment
to get the best results

Now it's time to think about how best to set up your science fair experiment to give you accurate and trustworthy results. You should keep in mind both the Scientific Method and the question you are trying to answer.

An experiment is made up of two nearly identical parts--let's say, two trays of tomato plants. The tiny differences that will test your hypothesis are called "variables." Let's look at the three kinds of variables.