Problem 1: How do between-subjects and within-subjects designs differ? What are two advantages of a between-subjects design?
Problem 2: Describe the three key components of experimental control.
Problem 3: With anxiety as an example, illustrate the difference between independent variables that are a) manipulated variables (true IVs) and b) subject variables (quasi IVs).
Problem 4: When a study uses subject variables (quasi IVs), causal conclusions cannot be drawn. Why not?
Problem 5: Describe how quasi-experimental designs differ, overall, from true experimental designs.
Problem 6: What is a switching replication design, and how does it help to rule out threats to internal validity.
Problem 7: First, identify the independent and dependent variables for each of the following. Then decide whether it would be more appropriate to use a between-subjects design or a within-subjects design, given the limited information presented for each study. Explain your choice.
a. A cognitive psychologist interested in the development of memory studies (annually) the short-term memory capacity of the same 20 children as they grow from age 4 through age 8.
b. To determine whether there is universality to facial expressions of emotions, a researcher prepares pictures of people from three different cultures, each showing the same variety of expressions (e.g., smile, scowl). On a given trial of the study, a participant looks at a photo and then chooses a matching emotion from a list of ten different emotions.