Rivier UniversityPSY 206 1) Three requirements of an experiment are randomization, manipulation, and the inclusion of a comparison or control group

Rivier UniversityPSY 206

1) Three requirements of an experiment are randomization, manipulation, and the inclusion of a comparison or control group. Which of these requirements is not met when we use the within-subjects design? Explain.

2. What are the two ways that researchers compensate for not using random assignment in a within-subjects experimental design?
3. Explain why each of the following order effects is a threat to internal validity.
   1. Carryover effect
   2. Participant fatigue
4. State whether each of the following is an example of a between-subjects design or a within-subjects design.
   1. A sample of expert chess players is asked to rate the effectiveness of six different playing strategies.
   2. A sample of children is randomly assigned to play with one of four types of toys during a reinforcement therapy session.

5.Which source of variation is removed from the denominator of the test statistic using the within-subjects design? Why is it removed?

6. What type of factorial design is described in each of the following situations?
   1. The same participants are observed in each group.
   2. Different participants are observed at each level of one factor and repeatedly observed across the levels of a second factor.
   3. Different participants are observed in each group.