3 In 1974 Loftus and Palmer conducted a classic study demons

3. In 1974, Loftus and Palmer conducted a classic study demonstrating how the language used to ask a question can influence eyewitness memory. In the study, college students watched a film of an automobile accident and then were asked questions about what they saw. One group was asked, “About how fast were the cars going when they smashed into each other?” Another group was asked the same question except the verb was changed to “hit” instead of “smashed into.” The “smashed into” group reportedly significantly higher estimates of speed than the “hit” group. Suppose a researcher repeats this study with a sample of today’s college students and obtains the following results.                                                                                                              

Estimated Speed

Smashed Into

Hit

n = 15

n = 15

M = 40.8

M = 34.0

SS = 510

SS = 414

Do the results indicate a significantly higher estimate for speed for the “smashed into” group? Use a one-tailed test with = .01.

Calculate the effect size.

Solution