Week 14 & 15.
Multivariate and within-subjects designs.
Typical designs assign subjects to one group (i.e., control or experimental) or the other. These are between-subjects designs. We will discuss different conditions when it is more informative for subjects to be in more than one condition, or to be measured more than once: "within subject" designs.
Understand the key forms of these designs:
- Own control
- Each participant is in both the control and experimental groups.
- Makes the contrast between conditions very clear & strong.
- Order of groups must be counterbalanced.
- .Reveral designs
- Test the hypothesis that a behavior is controlled by a specific temporary condition.
- Test it by imposing the condition (e.g., stress) on people, then withdrawing it, then imposing it again.
- Design: A - B - A / Impose - withdraw - Iimpose condition.
- Repeated measures and randomized block designs
- Multiple treatment conditions: each participant gets each treatment, similar to an "own control" design..
- Longitudinal / time sampling: each participant assessed over multiple time periods.
- Randomized block designs; Repeated measure combined with between-groups variable, e.g., an experimental group and a control group, each measured over time.
Lecture notes are here.
Chapter 11 & discussion of interpreting studies with multiple measured and unmeasured variables, and readings on interpreting “relative risk” statistics, and interpreting data about risks + benefits of mammography.
Discussion group Assignment
No discussion groups Week 14 for Thanksgiving
Discussion groups Week 15 will review for the exam and complete course evaluations.
Please bring a smart phone, tablet or computer to class!!