Test scores
A test contains only a sample of the tasks that students are expected to be able to do. On another sample of tasks designed to measure the same skills, the students might perform somewhat differently. Information provided on the score reports and in the ETS Proficiency Profile User's Guide (PDF) enables the user of the scores to determine how much the scores could be expected to differ if a different set of tasks were used.
The reliability of the individual scores of students taking the Standard form — particularly the skill area scores and the proficiency classifications — should be adequate for counseling purposes and for the identification of students with problems in particular skill areas. These scores cannot be used as the basis for high-stakes decisions about individual students.
Comparative data
The data in the Comparative Data Guide are drawn entirely from institutions that use the ETS Proficiency Profile. Within any category of institutions, those that use the ETS Proficiency Profile are not likely to be representative of all institutions in that category. In addition, the numbers of students tested and the sampling procedures vary from one institution to another, and it is impossible to verify that the students tested at each institution are representative of all the institution’s students at the relevant class level (freshman, sophomore, etc.).