Psych 250 Spring 2012
Homework Chapter 10
10 points
1. Renee (a 24-year-old master’s student) was studying attitudes toward women using a questionnaire about affirmative action for women. She hypothesized that male participants would express more support for affirmative action for women when they expressed their attitudes toward a female experimenter, compared to a male experimenter. Renee randomly assigned a group of male college students to have their questionnaire administered by her or by her male advisor, a 50-year-old professor of psychology. She conducted the study in two identical classrooms at the same time of day. Renee found that the men tested in her own room reported more support for affirmative action for women, compared to the men tested by her advisor. She concluded that the gender of the examiner can make men express more liberal gender attitudes.
a. Identify the independent variable (IV) and dependent variable (DV).
b. Identify the design (posttest-only? one-group, pretest/posttest? within-groups?).
c. Sketch a graph of the results. (Reminder: Put the dependent variable on the y-axis.)
d. Decide whether the study is subject to any of the internal validity threats listed in Table 10.1.
e. Indicate whether you could redesign the study to correct or prevent any of the internal validity threats.
2. Individual differences could obscure a true difference between groups. Apply this principle to the example of the GRE study described in Chapter 10, pp. 294. Using your understanding of individual differences, determine what individual differences might be relevant to the GRE preparation course. That is, what individual differences might interfere with your ability to see group differences in GRE scores? Could you use a repeated-measures design to control for these individual differences? Why or why not? How would a matched-pairs design help control for individual differences in the GRE prep course study? What steps would be necessary to complete a matched-pairs design?
For the next three questions, identify the independent & dependent variables, the levels of each independent variable, and find threats to the internal validity of each experiment.
3. A testing company is trying to determine if a new type of driver (club 1) will drive a golf ball greater distances than three competing brands (clubs 2 – 4). Twenty male golf pros are recruited. Each golfer hits 50 balls with club 1, then 50 more with 2, then 50 with club 3, then 40 with 4. To add realism, the experiment takes place over the first four holes of an actual golf course – the first set of 50 balls is hit from the first tee, the second 50 from the second tee, and so on. The first four holes are all 380 - 400 yards in length, and each is a par 4 hole.
4. A researcher is interested in the ability of schizophrenic patients to judge different time durations. It is hypothesized that loud noise will adversely affect their judgments. Participants are tested two ways. In the “quiet” condition, some participants are tested in a small soundproof room that is used for hearing tests. Those in the “noisy” condition are tested in a nurse’s office where a stereo is playing music at a constant (and loud) volume. Because of scheduling problems, locked-ward (i.e., slightly more dangerous) patients are available for testing only on Monday, and open-ward (i.e., slightly less dangerous) patients are available for testing only on Thursday. Furthermore, hearing tests are scheduled for Thursdays, so the soundproof room is available only on Monday.
5. An experimenter is interested in whether memory can be improved if people use visual imagery. Participants (all female) are placed in one of two groups – some are trained in imagery techniques, and others are trained to use rote repetition. The imagery group is given a list of 20 concrete nouns (for which it is easier to form images than abstract nouns) to study, and the other group is given 20 abstract words (ones that are especially easy to pronounce, so repetition will be easy), matched with the concrete words for frequency of general usage. To match the method of presentation with the method of study, participants in the imagery group are shown the words visually (on a computer screen). To control for any “compu-phobia,” rote participants also sit at the computer terminal, but the computer is programmed to read the lists to them. After hearing their respective word lists, participants have 60 seconds to recall as many words as they can in any order that occurs to them.