Questionnaire discrimination: (re)-introducing coefficient delta.

ABSTRACT:

Background

Questionnaires are used routinely in clinical research to measure health status and quality of life. Questionnaire measurements are traditionally formally assessed by indices of reliability (the degree of measurement error) and validity (the extent to which the questionnaire measures what it is supposed to measure). Neither of these indices assesses the degree to which the questionnaire is able to discriminate between individuals, an important aspect of measurement. This paper introduces and extends an existing index of a questionnaire's ability to distinguish between individuals, that is, the questionnaire's discrimination.

Methods

Ferguson (1949) 1 derived an index of test discrimination, coefficient delta, for psychometric tests with dichotomous (correct/incorr

SUBMITTER: Hankins M 

PROVIDER: S-EPMC1884165 | biostudies-literature | 2007 May

REPOSITORIES: biostudies-literature