In a classic study, Loftus and Palmer (1974) investigated the relationship between memory for eyewitnesses and the questions they are asked. In the study, participants watched a film of an automobile accident and then were questioned about the accident. One group was asked how fast the cars were going when they “smashed into” each other. A second group was asked about the speed when the cars “hit” each other, and a third group was not asked any question about the speed of the cars. A week later, the participants returned to answer additional questions about the accident, including whether they recalled seeing any broken glass. Although there was no broken glass in the film, several students claimed to remember seeing it. The following table shows the frequency distribution of responses for each group.

Response to the Question Did You See Any Broken Glass?

Yes No Verb Used to Ask About the Speed Smashed into 16 34 Hit 7 43 Control

(Not Asked)

6 44

a. Does the proportion of participants who claim to remember broken glass differ significantly from group to group? Test with a 5 .05.

b. Compute Cramér’s V to measure the size of the treatment effect.

c. Describe how the phrasing of the question influenced the participants’ memories.

d. Write a sentence demonstrating how the outcome of the hypothesis test and the measure of effect size would be reported in a journal article.