Case 2: In an effort to determine the effectsof the drug chlorpromazine on the performance of schizophrenics,two clinical investigators randomly selected 20 acuteschizophrenics from a mental hospital population. The patients wereasked to order several stimuli along some dimension, such asordering eight stimuli by weight. There were several tasks of thissort. All subjects first performed the tasks after being injectedwith a saline solution (Placebo) and then performed the tasks againseveral hours later after being injected with chlorpromazine. Theresults indicated that fewer errors were made in the chlorpromazinetreatment, which suggested to the investigators that the drugfacilitates more adequate cognitive functioning in this type ofpatient.

What do you think the hypothesis might be for this study? Is thehypothesis you selected directional or nondirectional? Why did youselect a directional or nondirectional hypothesis?

Next, discuss this study's design. What was the design? Was itappropriate? Why or why not?

What was the purpose of random selection in this study?

What is the independent variable? What is the dependent variableand how is it measured?

Are there possible confounds in this study? If so, how would youcontrol for them?