For each of the following, identify the independent and dependent variables and the levels of each independent variable, and find at least one extraneous variable that has not been adequately controlled (i.e., that is creating a confound). Be sure not to confuse internal and external validity. Use the format illustrated in Table 5.2.

Table 5.2

1. 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 3, then 50 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.

2. A researcher is interested in the ability of patients with schizophrenia to judge time durations. It is hypothesized that loud noise will adversely affect their judgment. Participants are tested two ways. In the “quiet” condition, some participants are tested in a small soundproof room 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.

3. An experimenter is interested in whether memory can be improved in older adults if they use visual imagery.

Participants (all women over the age of 65) 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 “computer‐phobia,”

rote participants also sit at the computer terminal, but the computer is programmed to read the lists to them. After the word lists have been presented, participants have a minute to recall as many words as they can in any order that occurs to them.

4. A social psychologist is interested in helping behavior and happens to know two male graduate students who would be happy to assist. The first (Felix) is generally well dressed, but the second (Oscar) doesn’t care much about appearances. An experiment is designed in which passersby in a mall will be approached by a student who is either well‐dressed Felix or shabbily‐dressed Oscar. All of the testing sessions occur between 8 and 9 o’clock in the evening, with Felix working on Monday and Oscar working on Friday. The student will approach a shopper and ask for a dollar for a cup of coffee.

Nearby, the experimenter will record whether or not people give money.

Transcribed Image Text:

Levels of IV Distribution of Practice 1 day 2 days 3 days EV 1 Study Hours 3 hours 6 hours 9 hours EV 2 Retention Interval 3 days 2 1 day days DV Retention Test Performance Lousy Average Great