On the Theory of Test Discrimination
- 1 March 1949
- journal article
- Published by Cambridge University Press (CUP) in Psychometrika
- Vol. 14 (1) , 61-68
- https://doi.org/10.1007/bf02290141
Abstract
This paper discusses the properties of distributions of test scores and advances the view that the properties of the distribution should depend on the function which the test is intended to perform. A theory of test discrimination is developed which defines discriminatory capacity in terms of the number of relations of difference established by the operation of administering a test of k items to a sample of n individuals. A simple proof is presented which indicates that maximum discrimination between individuals is achieved when tests are constructed to yield distributions of the rectangular form. A coefficient of test discrimination is developed. The problem of obtaining in practice distributions approximating to the rectangular form is briefly discussed.Keywords
This publication has 2 references indexed in Scilit:
- The Relation of Item Difficulty and Inter-Item Correlation to Test Variance and ReliabilityPsychometrika, 1945
- A Plea for a Functional Approach To Test ConstructionEducational and Psychological Measurement, 1943