Psychological Testing Characteristics of Psychological Tests

Why Test? These tests try to make it possible to find out a great deal about a person in a short amount of time What “movie” were you? Mr. Maida

Test Reliability Reliability - this refers to a tests consistency Three ways to determine reliability If you retake the same or a similar test a short time after taking the initial test, do you score about the same? Does the test get the same results when scored at different times by different people? Split-half – dividing test into two equal parts. Scores should be about the same

Test Validity Validity – the ability of a test to measure what it is intended to measure Does Tierney’s ability to swim a fast 50 free measure her grammar ability? Please say no Measuring validity is more difficult than reliability One method is to find out predictive validity (how well a test predicts performance) Is a “Keystone Exam” a valid measure of content knowledge?

What do both look like?

Test Standardization Standardization refers to two things: Must be administered and scored the same way every time Ever wonder why the SAT proctor reads from a script? Must establish the “norm,” or average score made by a large group of people

Establishing Norms Translating the score into something useful: If a you scored a 15 out of 25 on our first quiz what does that mean? Where do you stand in relation to the other students in the class? If most answered only 10 questions correctly that means that 10 correct is a very high score, right? Percentile System: Scores actually achieved are placed in order (you know this as the curve) Tests must be given to a large groups These percentiles are considered the “norms”