Scientific Controls: Why do we need controls and how do you find the right ones? The most important decision in the research process is determining the correct scientific controls. Scientists strive to control as many extraneous variables as possible. In today's ever growing scientific techniques, it can be difficult to determine if the best (or at least necessary) controls were used. Here I talk about the importance of controls and some types of controls that are still commonly in use. I also talk about how in some cases there is no right control, and in others, you need more than just a negative control.