Answer the following questions for each design critique:
a. What is (or could be) the independent variable(s) and what are its levels?
b. Is the independent variable a true IV or a subject variable?
c. What is (are) the dependent variable(s)?
d. What control variables were (or could be) used?
e. What needs to be done to improve the study?
1. A certain psychologist was looking for the cause of college failure. He took a group of former students who had flunked out and a group who had received good grades. He gave both groups a self-esteem test and found that the who failed scored lower on the test than the college success group. He concluded that low self-esteem is one of the causes of college failure and further suggested that the low self-esteem person probably expects to fail and exhibits defeatist behavior in college-which eventually leads to his/her
failure.
2. It was hypothesized that sensory deprivation inhibits the intellectual development of animals. To test this hypothesis, an experimenter used 2 rats, each of which had just given birth to 8 pups. One rat and her litter were placed in a large cage with ample space and objects to explore. The second rat's pups were separated from the mother and each was placed in a separate cage. These cages were quite small and the only objects they could see or hear were the four walls and the food dispenser. After five months, both groups were tested in a multiple-T maze using food as a reward. Following 20 trials, all of the non- deprived pups were running the maze without error, but the deprived pups were still making several errors. This latter group frequently froze and had to be prodded to move. The experimenter concluded that sensory deprivation inhibits intellectual development such that deprived rats did not have the intellectual ability to learn even a simple maze.
3. An investigator hypothesized that people in a fearful situation desire to be with other individuals. To test her hypothesis, the researcher randomly assigned 50 participants to either a high or low fear group. Participants in the low fear group were told that they would be shocked but that they would experience only a small tingle that would not hurt. Participants in the high
fear group were told that the shock would be quite painful and might burn the skin, but would not cause any permanent damage. After being told this, 8 participants in the high fear group declined to participate in the study. The researcher released them (as she was ethically bound to do) and conducted the experiment. Each group of participants was then told to wait while the shock
equipment was being prepared and that they could wait either in a room by themselves or with other people. No difference was found in the extent to which the high or low fear groups wanted to wait with others.