After reading Chapter 8 participate in the activity below to improve your knowledge of threats to internal validity/confounding variables. Read the appropriate scenario and then answer the questions below.
• Students whose last names begin with A – L, work on Confound 1.
Confound 1: A drug company developed a new medication to control the manic phase of bipolar manic-depression. The firm hired a hospital psychiatrist to test the effectiveness of the drug. He identified a group of manic-depressive patients and randomly assigned them to a drug or placebo group. Nurse Ratched was told to administer the drug and Nurse Johnson was told to administer the placebo. Each nurse made daily observations of her patients during treatment. A month later the observations were compared. In general, patients in the drug group had behaved more “normally” than patients in the placebo group. The drug company publicized its product’s effectiveness.
• Students whose last names begin with M – Z, work on Confound 2.
Confound 2: An investigator was interested in studying the effect of taking a course in child development upon attitudes toward childbearing. At the end of the semester, the researcher distributed a questionnaire to students who had taken the child development course. Questionnaires were also given to an equal number of students who had not taken the course. The students who had taken the child development course had different attitudes from the students who had not taken the course (e.g., they had more positive attitudes about having large families).
Answer the following questions:
1. Identify the independent variable(s).
2. Identify the dependent variable(s).
3. Identify any confounding variable(s).
4. Propose a method to “unconfound” the experiment.
If you think a previous student has made a mistake, please be sure to comment; don’t be afraid to make an alternate solution to these problems.