What is the difference between an independent and dependent variable in an experiment?

In experimental research, an independent variable is a variable that is manipulated by the researcher, while a dependent variable is the outcome that is measured. In other words, the independent variable is the presumed cause, and the dependent variable is the effect that is being studied. For example, in an experiment on the effect of caffeine on reaction time, caffeine would be the independent variable, as it is being manipulated by the researcher. The dependent variable, in this case, would be reaction time, as it is being measured as an outcome of caffeine consumption.

It is important to control for extraneous variables that could influence the outcome of the experiment. For instance, in the example above, factors such as time of day, the type of task being performed, and individual differences in reaction time should be controlled to isolate the effect of caffeine on reaction time.

The independent and dependent variables are critical components of experimental research, and they are essential for drawing valid conclusions about cause-and-effect relationships. By controlling the independent variable and measuring the dependent variable, researchers can draw conclusions about whether changes in the independent variable cause changes in the dependent variable.