Which of the following might contain a serious threat to the external validity of a study?
A) a survey with a return rate of 30%
B) statistically significant findings in both the clinical setting and at home
C) evidence of a consistent effect in the winter and the spring
D) evidence that shows SAT scores and GPA change with improved study habits

Question

Quizplus · Accepted Answer

A low return rate on a survey (30%) can lead to a non-representative sample, which threatens the external validity of a study by limiting the generalizability of its findings to the broader population.

Which of the Following Might Contain a Serious Threat to the External