1. In each of the experiments described here, specify the following: IV, DV, Population, Sample, Data, Statistic and Parameter.

a. A physiologist wants to know whether a particular region of the brain (the hypothalamus) is involved in the regulation of eating. An experiment is performed in which 30 rats are selected from the university vivarium 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 composed to see whether the lesions in the hypothalamus have affected the amount eaten.

b. A clinical psychologist is interested in evaluating three method of treating depression: medication, cognitive restructuring, and exercise. A fourth treatment condition, a waiting-only treatment group, is included to provide a baseline control group. Sixty depressed students are recruited from the undergraduate 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 designed to measure the degree of depression. The questionnaire is scaled from 0 to 100, with higher mean depression values are then computed for the four treatments and compared to determine the relative effectiveness of each treatment.

c. A social psychologist is interested in determining whether individuals who graduated from high school but get no further education earns 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 the mean salary values are calculated for each group.

d. 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 in an 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.