Which term concerns whether the study design allows causal conclusions about observed relationships?

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

Answer: (C)

Internal validity is about whether the study’s design actually allows us to draw causal conclusions from what we observe. It focuses on whether the observed relationship between variables can be causally interpreted rather than merely associated. A design with strong internal validity controls for confounding factors, ensures that the cause precedes the effect, and minimizes biases that could create false impressions of causation. For example, a randomized experiment bolsters internal validity because random assignment helps balance other variables that might influence the outcome, making it more plausible that observed differences are caused by the treatment rather than by something else. In observational studies, achieving high internal validity requires careful design and analysis to address potential confounders and alternative explanations, which is often more challenging.

Empirical research is a broad term for collecting data to study phenomena, but it doesn’t specify whether the design can support causal conclusions. A research question is what you’re trying to learn, not whether your design can establish causality. Difference-in-Differences is a specific analytic method that can help infer causality in certain setups, but the underlying concept asked about is the overall study design’s ability to support causal conclusions, which is internal validity.