In research, what does internal validity refer to?

Internal validity refers to the extent to which a study accurately measures the relationship between the independent variable and the dependent variable. It essentially indicates whether the changes in the dependent variable can be directly attributed to the manipulation of the independent variable, while controlling for other potential confounding variables that could influence the results. High internal validity means that the research design effectively isolates the causal impact, allowing researchers to confidently claim that observed effects are due to the experimental conditions rather than other factors.

In contrast, other options focus on different aspects of research validity or methodology. The accuracy of the sample size relates more to statistical power and the ability to detect effects if they exist, rather than the internal relationships within the study itself. Generalizability to different populations addresses external validity, which concerns how applicable the study’s findings are beyond the specific sample studied. Finally, consistency in data collection methods speaks to reliability rather than internal validity; it ensures that measurements are stable and repeatable but does not specifically address causal relationships.