HE201 Lecture 19: HE201 Lecture 19
Document Summary
Reliability & validity: reliability/precision: consistent answers are given to similar questions. Look for internal consistency (cronbach"s alpha, kr-20) and test-retest reliability: validity/accuracy: the responses or measurements are correct, content (logical) validity: subject matter experts agree that the questionnaire captures the most relevant details about the study domain. Trying to measure depression (vague topic) many components that need to be tested: construct validity: the test measures the theoretical construct it intended to assess. All questions together are an accurate measure of depression: criterion (concrete) validity: a new test yields results similar to a standard test for a similar theoretical construct. The way of testing a new scale matches the construct of the previous standard test (if designing a new way to measure depression) Types of variables: a variable is a characteristic that can be assigned more than one value, there are several ways to classify variables: Ratio variables: measures on a scale, has a meaningful 0 value.
