The document discusses external validity in research, emphasizing the importance of generalizing study results across different populations. It notes that studies lacking external validity are only valid for their tested samples and suggests using random and heterogeneous samples to enhance validity. This highlights the significance of sample selection in research design.

1. 
 How well the results of a study can be generalized
across populations.
 A study that lacks external validity cannot be
projected to other situations; it is valid only for the
sample tested.
 Usually associate to sample selection.
 Use random samples.
 Use heterogeneous samples.
10/14/2022
External Validity
Muhammad Awais
(facebook.com/awwaiis)