The Case of the Editor's Genie

Abstract

Professor Hanna Farrah is editor of the Journal of Useftl Treatments. One night as she opens an envelope resembling an article submission, a genie emerges from the envelope, saying, In return for letting me out of the envelope, I'll offer you several articles for your journal! All of the articles test the newest integrated treatment package, namely Biopsychosocial (Works) version 2, and all used the same set of measuring devices. All have adequate sample size and data analysis, so the only real distinguishing feature is design. I'll tell you the design of the studies, and you rate them in order of your preference. Here are the designs of the studies that the genie offered Professor Farrah: 1. The researchers got a group of families to sign up. There was no control group. Then, without doing any treatment, the researchers measured the outcome variables once a month, for 4 months. Then they gave the families the Works intervention, which has its effect within a month. Then they did the monthly measurement once more. The researchers compared the average monthly change before intervention, to the change during the month after the intervention. Diagramed: OOOOXO Where 0 stands for measurement, and X stands for intervention. 2. Families were randomly assigned to treatment or control groups and were not pretested. Both groups were posttested a month after treatment was given to one of the groups and the other was on the waiting list. The data were analyzed by comparing the mean scores of the two groups after the intervention. RXO R 0 Each line stands for a group; R stands for random assignment; o stands for measurement; X stands for intervention. 3. The researchers went to a community where the Works treatment was offered. They were able to locate many families who had chosen to get the treatment and many other families who had chosen not to get it. They