Threats to External Validity

Any factors within a study that reduce the generalizability of the results

1. Selection biases: Whether the sample or selection of participants are representative of the populations they are drawn from.

2. Construct biases: Whether the measurement of the construct can be generalizable or is representative of the behavior itself. See “Threats to Construct Validity” above.

3. The ‘real world’ vs the ‘experimental world’: Whether the study procedures are representative of the real world the study is attempting to mimic.

4. 4History effects and maturation: Whether the timing of the study (in history and the length of the study itself) can be generalized to other studies with other timings (e.g., a different year).