1. In 1974, Loftus and Plamer conducted a classic study demonstrating how the language used to ask a question can influence eyewitness memory. In this 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 reported significantly higher estimates of speed than the “hit” group. Suppose a researcher reports 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 mean for the “smashed into” group? Use a one-tailed test with α = .01. Please, show all calculations and explanations.
2. Steven Schmidt, conducted a series of experiments examining the effects of humor on memory. In one study, participants were given a mix of humorous and non-humorous sentences and significantly more humorous were recalled. However, Schmidt argued that the humorous sentences were not necessarily easier to remember, they were simply preferred when participants had a choice between the two types of sentence. To test this argument, he switched to an independent-measures design in which one group got a set of exclusively humorous sentences and another group got a set of exclusively non-humorous sentences. The following data are similar to the results from the independent- measures study.
Humorous sentences Non humorous sentences
4 5 2 4 6 3 5 3
6 7 6 6 3 4 2 6
2 5 4 3 4 3 4 4
3 3 5 3 5 2 6 4
Do the results indicate a significant difference in the recall of humorous versus non-humorous sentences? Use a two tailed test with α =.05.