Discussion:
Repeated Measures Design
There are many situations that psychologists encounter where there are very few subjects in the population of interest. For example, perhaps a psychologist is looking to develop and intervention for teenagers who engage in self-mutilation. This disorder occurs relatively rarely, at a rate of about 18 people (ages 18 to 35) per 1000 people (Suyemoto and MacDonald, 1995) . If we assume that about half that number fall into the age range of interest, we are looking at maybe 9 teenagers per 1000 people in the general population. This would make for a very small subject pool.
what other populations can you think of that are so small, that it would benefit a researcher to consider using a repeated measures design for their study?