What does internal validity refer to in the context of experimental studies?

Internal validity refers to the trustworthiness of cause-and-effect relationships in experimental studies. It evaluates how well a study is designed to eliminate confounding variables that could obscure the true relationship between the independent and dependent variables. A study with high internal validity means that any changes observed in the dependent variable can confidently be attributed to manipulations of the independent variable, rather than to other external factors.

Establishing internal validity is crucial for ensuring that the conclusions drawn from the study accurately reflect the causal connections intended to be tested. This concept is vital in experimental design, as it validates the integrity of the findings and supports scientific claims. In contrast, factors affecting generalizability, emotional responses of subjects, or the statistical methods employed, while important, do not fundamentally address whether the causal relations established in the experiment are reliable and valid.