What term refers to influential factors other than those of primary interest by which treatment and control groups are likely to differ?

The term that refers to influential factors other than those of primary interest, by which treatment and control groups are likely to differ, is known as lurking variables. These are variables that are not included in the analysis but can still have an effect on the relationship being studied. They can introduce bias and confound the results, leading to erroneous conclusions if not accounted for.

Understanding lurking variables is crucial in experimental design and data analysis because they can mask the true effects of the independent variable on the dependent variable. By identifying and controlling for these additional factors, researchers can obtain more reliable and valid results. This concept plays a significant role in various fields such as statistics, epidemiology, and social sciences, where establishing causal relationships is essential.

The other terms do not accurately describe these influential factors. Independent variables are those that are manipulated to observe their effect on dependent variables, while dependent variables are the outcomes that are measured after manipulation. Experimental variables refer to the elements of the experiment that are deliberately altered or kept constant. Lurking variables, however, are those that operate in the background and can impact the results without being directly measured or manipulated.