What term refers to some aspect of the experimental situation that is manipulated by the researcher?

The term that describes an aspect of the experimental situation that is manipulated by the researcher is known as the independent variable. In an experiment, the independent variable is the variable that is changed or controlled in order to test its effects on the dependent variable. By altering the independent variable, the researcher can observe how it influences the outcome, thus establishing a cause-and-effect relationship.

This is fundamental in experimental design, as manipulating the independent variable while keeping other factors constant allows for a clear understanding of the results. In comparison, control variables are kept constant to minimize their effect on the dependent variable, while extraneous variables are external factors that might introduce error or influence the results if not controlled. The dependent variable, on the other hand, is the outcome that is measured in response to changes in the independent variable.