PSYC 3250 Lecture Notes - Lecture 16: Standard Deviation, The Item, Psychometrics

• School: University of Guelph
• Department: Psychology
• Course: PSYC 3250
• Professor: David Stanley

Document Summary

Item analysis technique for quesions with right/wrong answers. Some items are beter than other at measuring the atribute in quesion. Part of test development is choosing the best items for your inal test. A loosely structured group of staisics that can be computed for each item in a test. The exact choice and interpretaion of the staisics that make up an item analysis are determined by the purpose and nature of the test and the test developer"s objecives. Purpose: an item analysis can show why a test is reliable (or unreliable, can suggest ways of improving the measurement characterisics of a test. Item analysis techniques for quesions with right/wrong answers: item diiculty, item discriminaion, distractor analysis. Item analysis technique for self-report scales: item mean, corrected item-total correlaion. Item analysis techniques for either right/wrong answers or self-report scales: item reliability index, cronbach"s alpha.