Dr. Kang, a cognitive psychologist, conducts an experiment examining the effect of emotion on memory. He provides lists of 15 words to two groups of participants at his university. He puts the names of all the participants in a hat. The first 20 names he assigns to Group A and the last 20 he assigns to Group B. Group A is given a list of words that are very emotional in content (e.g., passion, murder). Group B is given a list of words that are neutral in content (e.g., houseplant, desk). He then measures how many words each group is able to remember after being distracted for 5 minutes by watching a video about the history of the university. He finds that Group A remembers 15% more words than Group B.
Dr) Kang's decision to assign participants randomly to Group A and Group B increases which of the following?
A)the covariance of the study
B)the temporal precedence of the study
C)the internal validity of the study
D)the external validity of the study

Question

Quizplus · Accepted Answer

Random assignment to groups increases the internal validity of the study because it ensures that any differences observed in the dependent variable (memory) are due to the independent variable (emotional vs neutral words) and not due to pre-existing differences between the groups. This makes it more likely that the study is measuring what it is intended to measure. Random assignment does not directly affect covariance, temporal precedence, or external validity.

Dr Kang, a Cognitive Psychologist, Conducts an Experiment Examining the Effect