ERIC Number: EJ690011
Record Type: Journal
Publication Date: 2004-Jun
Pages: 18
Abstractor: Author
ISBN: N/A
ISSN: ISSN-0013-1644
EISSN: N/A
The Impact of Missing Data on Sample Reliability Estimates: Implications for Reliability Reporting Practices
Enders, Craig K.
Educational and Psychological Measurement, v64 n3 p419-436 Jun 2004
A method for incorporating maximum likelihood (ML) estimation into reliability analyses with item-level missing data is outlined. An ML estimate of the covariance matrix is first obtained using the expectation maximization (EM) algorithm, and coefficient alpha is subsequently computed using standard formulae. A simulation study demonstrated that the EM approach yields (a) less bias in reliability estimates, (b) dramatically reduces cross-sample fluctuation of estimates, and (c) yields more accurate confidence intervals. Implications for reliability reporting practices are discussed, and the EM procedure is demonstrated using a heuristic data set.
Descriptors: Intervals, Simulation, Test Reliability, Computation, Maximum Likelihood Statistics, Data Analysis, Error of Measurement, Measurement Techniques, Test Items, Item Analysis
Sage Publications, 2455 Teller Road, Thousand Oaks, CA 91320. Tel: 800-818-7243 (Toll Free); Fax: 800-583-2665 (Toll Free).
Publication Type: Journal Articles; Reports - Research
Education Level: N/A
Audience: N/A
Language: English
Sponsor: N/A
Authoring Institution: N/A
Grant or Contract Numbers: N/A

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