Cohort

Essentially, cohort refers to people who are approximately the same age. When researchers conduct different types of studies (for example, developmental/cross sectional studies), they use cohorts to see how people of different ages compare on some topic at one point in time. For example, a researcher may compare the effects of a new study aid in three different cohorts: 10th graders, 11th graders, and 12th graders. In this way, you can examine the study aid across three different grade levels.