What is the role of the independent variable in an experiment?

The independent variable in an experiment is the factor that the experimenter manipulates or controls to observe its effects on other variables. It is the variable that is deliberately changed or varied to see how it impacts the dependent variable, which is the outcome being measured. By controlling the independent variable, researchers can establish cause-and-effect relationships.

For instance, if a study is examining the effects of different diets on weight loss, the type of diet would be the independent variable because the researcher decides which diet each group will follow. The changes in weight loss would be the dependent variable, as it is what is being observed and measured in response to the different diets.

The other options refer to aspects of experimental design but do not accurately define the role of the independent variable. The outcome being measured corresponds to the dependent variable, variables that remain constant are referred to as controlled variables, and variables not accounted for in the study can be considered confounding variables, which may introduce bias or variability to the results.