EVERYDAY SCIENCE

Detailed explanation-1: -There must be at least two variables in any experiment: a manipulated variable and a responding variable. A manipulated variable is a variable that is changed by the researcher. A manipulated variable is also called an independent variable.

Detailed explanation-2: -One is called the dependent variable and the other the independent variable. The independent variable is the variable the experimenter manipulates or changes, and is assumed to have a direct effect on the dependent variable.

Detailed explanation-3: -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 insure a fair test, a good experiment has only ONE independent variable.

Detailed explanation-4: -In factorial research designs, experimental conditions are formed by systematically varying the levels of two or more independent variables, or factors. For example, in the classic two × two factorial design there are two factors each with two levels.

Detailed explanation-5: -Answer and Explanation: You can have as many independent variables in an experiment, as you want, but you would like to design your experiments to have only one independent variable if it is possible. This is because it allows you to determine whether your independent variable influences your dependent variable.