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ERIC Number: EJ1087862
Record Type: Journal
Publication Date: 2015
Pages: 4
Abstractor: As Provided
ISSN: ISSN-0731-1745
Delimiting Coefficient a from Internal Consistency and Unidimensionality
Sijtsma, Klaas
Educational Measurement: Issues and Practice, v34 n4 p10-13 Win 2015
I discuss the contribution by Davenport, Davison, Liou, & Love (2015) in which they relate reliability represented by coefficient a to formal definitions of internal consistency and unidimensionality, both proposed by Cronbach (1951). I argue that coefficient a is a lower bound to reliability and that concepts of internal consistency and unidimensionality, however defined, belong to the realm of validity, viz. the issue of what the test measures. Internal consistency and unidimensionality may play a role in the construction of tests when the theory of the attribute for which the test is constructed implies that the items be internally consistent or unidimensional. I also offer examples of attributes that do not imply internal consistency or unidimensionality, thus limiting these concepts' usefulness in practical applications.
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Publication Type: Journal Articles; Reports - Evaluative
Education Level: N/A
Audience: N/A
Language: English
Sponsor: N/A
Authoring Institution: N/A
Grant or Contract Numbers: N/A