1 or 2 questions a, b, c, or ab, or ac, etc formulas know what it is, why we use it, and when we use, will not need to compute it or identify variables. Midterm some conceptual, some concrete questions all content will be tested. 70% of people are below the score of the test taker score of 123 is at the 70% percentile. Classical test theory: theory x = t + e, x actual observation (data that is collected) represents test takers, t, e. Some uses of tests job selection, performance appraisal, vocational interests, career management, clinical diagnosis, and educational assessment medical and health practice. Psychometrics psychometrics science of psychological measurement usually involves measuring things we cannot see need to something that we cannot see observable. 2 = unemployed: use numbers as a convenient way to represent group membership.