If you test applicability beyond the sample, this concerns which concept?

• A. Internal Validity
• B. Empirical Research
• C. External Validity
• D. Difference-in-Differences

Answer: (C)

External validity is about whether findings generalize beyond the studied sample to other people, settings, or times. When you test applicability beyond the sample, you’re asking if the observed effect would hold in different populations or in different environments, not just under the exact conditions of the study. This concerns generalizability: can the results be applied outside the specific group and context you studied?

Understanding this helps explain why a result might appear strong in one study but fail to replicate elsewhere if the sample or setting isn’t representative or if context changes alter the effect. To bolster external validity, researchers aim for diverse, representative samples, test the phenomenon across varied settings, and consider replication in different times or contexts.

Internal validity, by contrast, is about whether the study correctly establishes a causal relationship within its own design, free from confounding. Empirical research is a broad umbrella for collecting data and testing hypotheses, not a specific issue by itself. Difference-in-Differences is a method for causal estimation over time between treated and control groups, but it does not by itself address whether results generalize beyond the study sample.