While participating in a lengthy experiment involving job training for welfare recipients,the economy enters into a major recession.Posttest measurements found that job training was unsuccessful in helping participants locate jobs.However,the experiment's designers claim that the findings were inconclusive because of internal invalidity.Which of the following sources of internal invalidity would they be most likely to name as the problem?
A)contamination
B)history effect
C)selection bias
D)the Hawthorne effect

Question

Quizplus · Accepted Answer

The economy entering into a major recession is a historical event that could have had a significant impact on the outcome of the study. Participants may have had difficulty finding jobs due to the overall economic downturn rather than lack of job training. This is an example of a history effect, which can contribute to internal invalidity. The other options (contamination, selection bias, and the Hawthorne effect) are less likely sources of internal invalidity in this scenario.

While Participating in a Lengthy Experiment Involving Job Training for Welfare