In each of the experiments described here, specify (I) the independent variable, (2) the dependent variable, (3) the sample, (4) the population, (5) the data, and (6) the statistic:

a. A health psychologist is interested in whether fear motivation is effective in reducing the incidence of smoking. Forty adult smokers are selected from individuals residing in the city in which the psychologist works. Twenty are asked to smoke a cigarette, after which they see a gruesome film about how smoking causes cancer. Vivid pictures of the diseased lungs and other internal organs of deceased smokers are shown in an effort to instill fear of smoking in these subjects. The of her group receives the same treatment, except they see a neutral film that is unrelated to smoking. For 2 months after showing the film, the experimenter keeps re cords on t he n umber of cigarettes smoked daily by the participants. A mean for each group is then computed, of the number of cigarettes smoked daily since seeing the film, and these means are compared to determine whether the fear-inducing film had an effect on smoking. Health.

b. A physiologist wants to k now whether a particular region of the brain (the hypothalamus) is involved in the regulation of eating. An experiment is per-formed in which 30 rats are selected from the university atrium and divided into two groups. One of the groups receives lesions in the hypothalamus, whereas the other group gets lesions produced in a neutral area. After recovery from the operations, all animals are given free access to food for 2 weeks, and a record is kept of the daily food intake of each animal. At the end of the 2-week period, the mean daily food intake for each group is determined. Finally, these means are compared to see whether the lesions in the hypothalamus have affected the amount eaten. Biological.

c. A clinical psychologist is interested in evaluating three methods of treating depress ion: medication, cognitive restructuring, and exercise. A fourth treatment condition, a waiting-only treatment group, i s included to provide a baseline control group. Sixty depressed students are recruited from t he under-graduate student body at a large state university, and fifteen are assigned to each treatment method. Treatments are administered for 6 months, after which each student is given a questionnaire de -signed to mea sure t he degree of depress ion. The questionnaire is scaled from 0 to 100, with higher scores indicating a higher degree of depression. The mean depression values are then computed for the four treatments and compared to determine the relative effectiveness of each treatment. clinical, Health.

d. A social psychologist is interested in determining whether individuals who graduate from high school but get no further education earn more money than high school dropouts. A national survey is conducted in a large Midwestern city, sampling 100 individuals from each category and asking each their annual salary. The results are tabulated, and mean salary values are calculated for each group. Social

e. A cognitive psychologist is interested in how retention is affected by the spacing of practice sessions. A sample of 30 seventh graders is selected from a local junior high school and divided into three groups of 10 students in each group. All students are asked to memorize a list of 15 words and are given three practice sessions, each 5 minutes long, in which to do so, Practice sessions for group 1 subjects are spaced 10 minutes apart; for group 2, 20 m Mutes apart; and for group 3, 30 m mutes apart. All groups arc given a retention test 1 hour after the last practice session. Results are recorded as the n umber of words correctly recalled i n the test period. Mean values are computed for each group and compared. Cognitive

f. A sport psychologist uses visualization in promoting enhanced performance in college athletes. She is interested in evaluating the relative effectiveness of visualization alone versus visualization plus appropriate s elf-talk. An experiment is conducted with a college basketball team. Ten members of the team are selected. Five are assigned to a visualization a lone group, and five are assigned to a visualization plus self-talk group. Both techniques are designed to increase foul shooting accuracy. Each group practices its technique for I month. The foul shooting accuracy of each player is measured be-fore and 1 month after beginning practice of the technique. Difference scores are computed for each player, and the means of the difference scores for each group are compared to determine the relative effectiveness of the two techniques. I/O, Other

g. A typing teacher believes that a different arrangement of the typing keys will promote faster typing. Twenty secretarial trainees, selected from a large business school, participate inane experiment designed to test this belief. Ten of the trainees learn to type on the conventional keyboard. The other ten are trained using the new arrangement of keys. At the end of the training period, the typing speed in words per minute of each trainee is measured. The mean typing speeds are then calculated for both groups and compared to determine whether the new arrangement has had an effect? Education