This chapter features five investigations from Starting Points presented in Chapter 1 and gives a scenario of “the test of a fair test” for each. If a test is a fair test, it is expected to be repeatable. This is important and scientists often check for repeatability or reproduceability. This helps scientists decide if the test is indeed fair. It’s important to check experiments to see if you get almost the same results—repeatability—when you do the same experiment. If the results are not about the same, then something must be different. To control your experiment, you will need to find out how to get similar results each time.