Question

What is a repeated measures design? Describe an example in which you would use any type of t-test with a repeated measures design.

Answer 1

We know that,

Repeated measures design is a research design that involves multiple measures of the same variable taken on the same or matched subjects either under different conditions or over two or more time periods. For instance, repeated measurements are collected in a longitudinal study in which change over time is assessed.

Example of t-test with a repeated measures design is,

Experiment on the effect of alcohol on task
performance (time in seconds).
Measure time taken to perform the task for subjects
when drunk, and when (same subjects are) sober.
Null hypothesis: alcohol has no effect on time taken:
variation between the drunk sample mean and the
sober sample mean is due to sampling variation.
i.e. The drunk and sober performance times are
samples from the same population.

Thank you.