For each of the studies described below, give the following information. When the study is observational, describe the randomized design that the actual study seems to approximate most closely. Randomized experiment or observational study? Purpose and response(s) Units Blocking factors Treatment factors Name of the design (e.g. CR[4], CB[2]). Psychologists have suggested that “deeper and more elaborate processing” is an aid to memory (Hyde & Jenkins 1973, Journal of Verbal Learning and Verbal Behavior). In an experiment to test this theory, subjects saw a set of 24 words presented at a rate of 3 seconds per word. One group of subjects was asked to check whether each word had an “e” or “g” in it; the other group rated the pleasantness of each word. Each of these groups had been subdivided: half of each group thought the letter-checking or rating was the main task, while the other half had been told that they would be asked to recall as many words as they could. Once the initial task was over, all subjects were tested for recall.
