What is commonly measured to assess the effect of the independent variable in quasi-experimental designs?

The dependent variable is commonly measured to assess the effect of the independent variable in quasi-experimental designs. In research, the independent variable is the factor that is manipulated or varied to observe its effects, while the dependent variable is the outcome that is measured to determine whether the manipulation had an effect.

In quasi-experimental designs, researchers do not have full control over the assignment of participants to conditions, often due to ethical or practical constraints. Despite this limitation, measuring the dependent variable allows researchers to observe and analyze the relationship between the independent variable and the outcome. This is essential in evaluating the impact of interventions or changes in conditions that are not random assignments but still aim to identify causal relationships.

Considering the other options: random samples relate more to sampling methods rather than measuring outcomes; confounding variables refer to extraneous factors that may affect the dependent variable but are not the focus of measurement; and extraneous variables are those that researchers try to control or account for, rather than measures of the effect itself. Hence, the emphasis remains on the dependent variable in assessing the results of quasi-experimental designs.