When latané and darley replicated their experiment on behaviors as a field experiment, they had two burly men steal a case of beer from a convenience store, and then measured the number of customers who reported the robbery. why would they replicate their laboratory study in a field setting?

The answer is "to enhance external validity".

External validity is the validity of summed up (causal) inferences in scientific research, normally in view of examinations as experimental validity. It is the degree to which the aftereffects of an investigation can be summed up to different circumstances and to other people. Mathematical examination of external validity concerns an assurance of whether speculation crosswise over heterogeneous populaces is plausible, and contriving measurable and computational strategies that create substantial generalizations.

answer/// product differentiation;