A study manipulates and controls one or more independent variables to…

Concept

A causal research design tests whether deliberate variation in an independent variable produces a change in a dependent variable.

Manipulation introduces the planned variation, while control reduces alternative explanations so that the cause-and-effect link can be assessed.

Application

The study in the question both manipulates and controls independent variables and then measures change in a dependent variable. Those are the defining operations of experimental research.

Contrast

• Longitudinal research primarily distinguishes change across time through repeated observations; manipulation is not its defining feature.

• Archival research works with existing records or datasets rather than introducing a controlled intervention.

• A case study provides an intensive contextual examination of a bounded case and does not, by definition, require manipulation of variables.

Cross-check

If the manipulation were removed and the same participants were only observed repeatedly over time, the design would be longitudinal rather than experimental. The presence of deliberate manipulation and control confirms the classification.

Result

The described study is experimental research.