When external validity is low, the credibility of your research comes into doubt.

One way to increase external validity is by conducting field experiments.

Questions have been raised about the external validity of deindividuation research.

Both internal and external validity are not captured in a single experiment.

If the study has external validity then the study's findings have different settings, procedures, and participants.

The external validity may be less for at least two reasons:

By this means we may greatly enhance the external validity of the study (see Section 15.3).

Therefore, many critics dismiss the weapons effect due to its lack of external validity.

"A threat to external validity is an explanation of how you might be wrong in making a generalization."

Other social psychologists prefer external validity to control, conducting most of their research in field studies.