What is representativeness?

The term 'Representativeness' when used related to testing, means that a small sample that was tested from a larger group was so similar to the larger group (representative of the group) that one can assume that their range of scores would be very similar to the larger group if they had also been tested.  We recommend caution when attempting to generalize from small sample results to assumptions about the larger group (population) as a whole, unless the sample of test-takers can be shown to be representative of the larger population.  For example, the test results from a sample of 200 students, all of whom have volunteered to be tested, may not be representative of the larger population of students. Similarly, test scores from a sample of freshmen who are residential students may not be representative of the larger population of undergraduates, if this larger group includes distance learners, transfer students, and adult part time students.