Dr.Street wants to measure the effects of watching a movie on mood.He asks students to select either a comedy or a tragedy to watch in a controlled setting.He administers a mood test afterward and finds that the comedy group is significantly happier than the tragedy group.Dr.Street cannot make a causal statement about the effects of movies on mood because
A) he failed to manipulate a variable.
B) he failed to include a dependent variable.
C) he failed to randomly assign participants.
D) he found no correlation between movie and mood.

Question

Quizplus · Accepted Answer

Dr.Street did not randomly assign participants to the comedy or tragedy group, which means that there could be confounding variables that affect the results. Therefore, he cannot make a causal statement about the effects of movies on mood.

DrStreet Wants to Measure the Effects of Watching a Movie