Which term refers to the development processes within subjects over time that can affect study outcomes?

The correct term for the development processes within subjects that can influence study outcomes over time is maturation. Maturation refers to the natural progression of growth and development that individuals undergo, which can affect their responses, behaviors, and abilities during a study. This is especially relevant in longitudinal studies, where participants are observed over an extended period. Changes resulting from maturation may lead to outcomes that are not solely the result of the experimental manipulation or treatment being studied, but instead stem from the natural changes occurring within the participants as they age or develop.

In research, it is vital to account for maturation effects to ensure that any observed changes in a study are attributed to the interventions or variables being tested rather than to the subjects' natural developmental processes. Understanding and controlling for maturation helps researchers isolate the impact of their experimental conditions on study outcomes.