8.1: Repeated Measures Design
- Page ID
- 7933
Let’s use the exact same toy example from the previous chapter, but let’s convert it to a repeated measures design.
Last time, we imagined we had some data in three groups, A, B, and C. The data looked like this:
groups | scores |
---|---|
A | 20 |
A | 11 |
A | 2 |
B | 6 |
B | 2 |
B | 7 |
C | 2 |
C | 11 |
C | 2 |
The above table represents a between-subject design where each score involves a unique subject.
Let’s change things up a tiny bit, and imagine we only had 3 subjects in total in the experiment. And, that each subject contributed data to the three levels of the independent variable, A, B, and C. Before we called the IV groups
, because there were different groups of subjects. Let’s change that to conditions
, because now the same group of subjects participates in all three conditions. Here’s the new table for a within-subjects (repeated measures) version of this experiment:
subjects | conditions | scores |
---|---|---|
1 | A | 20 |
2 | A | 11 |
3 | A | 2 |
1 | B | 6 |
2 | B | 2 |
3 | B | 7 |
1 | C | 2 |
2 | C | 11 |
3 | C | 2 |