In experimental research, the independent variable is defined as

• A. influence or affect the outcomes in experimental studies
• B. are added together to determine the combined impact of the variables
• C. are the outcomes of a research study
• D. distinguish between groups in a study

Answer: (A)

In experimental research, you deliberately change a variable to see its effect on another variable. The independent variable is exactly that manipulated factor—the one you vary across conditions to observe what happens to the outcome. By controlling and altering this variable, you can attribute any observed differences in the results to that manipulation, rather than to other factors. The focus is on influencing the outcomes, not on what you measure as the result (that’s the dependent variable), not on adding variables together, and not on how groups are simply distinguished. If you’re asking what drives differences across conditions, the independent variable is the element you adjust to test its impact on the chosen outcome.