Did Luchins use an appropriate control group? If not, what should be the control condition?

Question #1. Reread the description of Luchins’ experiment outlined in Table 13.1. There seem to be several problems with that study; see whether you can pinpoint two or three of them. As a hint, consider the following questions: Did Luchins use an appropriate control group? If not, what should be the control condition? Are there points in the study that require counterbalancing? What additional dependent variables might have been informative?