Which type of validity assesses whether the independent variable really made the change in the dependent variable?

Internal validity is crucial in research as it determines whether the observed effect in the dependent variable can be confidently attributed to the manipulation of the independent variable. This type of validity focuses on establishing a cause-and-effect relationship within the study.

When researchers ensure that their study controls for confounding variables and biases, they strengthen internal validity. A high internal validity means that the results are more likely to reflect a true relationship, rather than being influenced by outside factors. This is particularly important in experimental research where the goal is to determine the impact of an intervention or treatment.

In contrast, external validity refers to the generalizability of the study findings beyond the specific context in which the research was conducted. Construct validity involves whether the tools used in a study accurately measure the theoretical constructs they are intended to measure. Content validity evaluates how well a test or tool covers the representative domain of the construct it aims to measure. While all these types of validity are important in their rights, internal validity specifically addresses the issue of causation between variables in a controlled environment.