different types of variables science
These changing quantities are called variables. A variable is any factor, trait, or condition that can exist in differing amounts or types. An experiment usually has three kinds of variables: independent, dependent, and controlled.The independent variable is the one that is changed by the scientist.To ensure a fair test, a good experiment has only one independent variable.n experiment usually has three kinds of variables: independent, dependent, and controlled. The independent variable is the one that is changed by the scientist. To ensure a fair test, a good experiment has only one independent variable.