# 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 |