PSY 370 Lecture Notes - Lecture 30: Psy
Document Summary
****do not make the assumption that all your items are homogeneous. You need to do a cfa first, and then you can calculate an internal consistency reliability. You need to figure out how many dimensions you have first and then it is possible to calculate internal consistency. Separate true score from error caused by idiosyncrasies in the questions. Would a person"s test score be different if you had chosen a different set of items. Do all the items point toward the same thing. All of the items are measuring one homogeneous construct. Need to estimate reliability separately for each component. Matching items to create two (hopefully) parallel halves. Score each half separately and correlate the two scores. The proportion of variance due to true scores. Tells you how well the two sets of items go together. Only gives you the reliability for half the test. So we need to correct this estimate to reflect the reliability of our entire test.
