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ERIC Number: EJ829948
Record Type: Journal
Publication Date: 2009-Mar
Pages: 16
Abstractor: As Provided
Reference Count: 0
ISSN: ISSN-0033-3123
Reliability of a Longitudinal Sequence of Scale Ratings
Laenen, Annouschka; Alonso, Ariel; Molenberghs, Geert; Vangeneugden, Tony
Psychometrika, v74 n1 p49-64 Mar 2009
Reliability captures the influence of error on a measurement and, in the classical setting, is defined as one minus the ratio of the error variance to the total variance. Laenen, Alonso, and Molenberghs ("Psychometrika" 73:443-448, 2007) proposed an axiomatic definition of reliability and introduced the R[subscript T] coefficient, a measure of reliability extending the classical approach to a more general longitudinal scenario. The R[subscript T] coefficient can be interpreted as the average reliability over different time points and can also be calculated for each time point separately. In this paper, we introduce a new and complementary measure, the so-called R[subscript lambda], which implies a new way of thinking about reliability. In a longitudinal context, each measurement brings additional knowledge and leads to more reliable information. The R[subscript lambda] captures this intuitive idea and expresses the reliability of the entire longitudinal sequence, in contrast to an average or occasion-specific measure. We study the measure's properties using both theoretical arguments and simulations, establish its connections with previous proposals, and elucidate its performance in a real case study.
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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