Chapter 9 Design Problems

For each or the following examples identify the type or experimental design (e.g., is it a one‑way ANOVA, a 2 X 2 factorial, a 3 X 3 X 2 mixed model, etc.). For each example, list the factors (stating how many levels each is and whether it is a between groups or repeated measures factor) and list all possible interactions.

1. A researcher wishes to examine the effects of high versus low incentives on performance accuracy on a task, in addition to determining the influence of administering the task before or after a large meal. One group of subjects is offered $10.00 for not making any errors and another is offered $1.00 for not making any errors. Both groups are tested before and after eating.

2. A clinical psychologist wants to know if brand A or brand B of an anti‑psychotic drug is better, and if either is better than a placebo. She administers Brand A to one group of psychotics, Brand B to another group, and a sugar pill to a third group. She recorded the number of psychotic episodes occurring in a one month period in each group.

3. A developmental psychologist wishes to find out whether children will be more likely to imitate the behavior of two models who act aggressively towards a bobo doll than two models who behave in different ways toward the doll (i.e., one model behaves aggressively and the other does not). He also wishes to know if the age of the models influences the likelihood of imitation of aggressive responses so in one case the models will be children and in the other the models will be adults. The researcher measures the number of aggressive acts by the subjects toward the bobo doll in a period of free‑play after viewing the models.

4. A social psychologist wishes to study how the number of people in a setting, the sex of the people, and the degree of acquaintance between the people effect how crowded a person feels. One group of subjects (one at a time) is placed in a room with four same‑sexed strangers, then in a room with eight same‑sexed strangers. They are asked to indicate how crowded they feel in each room. This same group of subjects is then placed in a room with four opposite‑sexed strangers, then in a room with eight opposite‑sexed strangers and again asked to indicate how crowded they feel. This same procedure is then followed with a second group of subjects, except that the four rooms in which they are placed all have good friends of the subject in them.

5. A researcher wishes to examine whether people high in self‑esteem conform less than people low in self‑esteem when they are led to believe that they are incompetent at a judgment task. One group of high‑self‑esteem subjects are led to believe that they are competent on the task while another is led to believe that they are incompetent. similarly, one group of low‑self‑esteem subjects are led to believe that they are competent and another led to believe that they are incompetent on the task. The researcher measures how much each of these groups conforms to other peoples' judgment on the task.

6. A researcher wishes to determine how the similarity of task performance influences two peoples' judgments about the causes of their own and other person's performance. one group of subject‑pairs is led to believe that they both did well on a test. Another group 0: subject‑pairs is led to believe that one of the pair did very well on the test while the other failed. Both groups of subject‑pairs are asked to attribute their own performance to ability vs luck, then to attribute their partner's performance to ability vs. luck.