An empirical evaluation of alternative methods of estimation for confirmatory factor analysis with ordinal data.

DB Flora, PJ Curran�- Psychological methods, 2004 - psycnet.apa.org
Psychological methods, 2004psycnet.apa.org
Confirmatory factor analysis (CFA) is widely used for examining hypothesized relations
among ordinal variables (eg, Likert-type items). A theoretically appropriate method fits the
CFA model to polychoric correlations using either weighted least squares (WLS) or robust
WLS. Importantly, this approach assumes that a continuous, normal latent process
determines each observed variable. The extent to which violations of this assumption
undermine CFA estimation is not well-known. In this article, the authors empirically study this�…
Abstract
Confirmatory factor analysis (CFA) is widely used for examining hypothesized relations among ordinal variables (eg, Likert-type items). A theoretically appropriate method fits the CFA model to polychoric correlations using either weighted least squares (WLS) or robust WLS. Importantly, this approach assumes that a continuous, normal latent process determines each observed variable. The extent to which violations of this assumption undermine CFA estimation is not well-known. In this article, the authors empirically study this issue using a computer simulation study. The results suggest that estimation of polychoric correlations is robust to modest violations of underlying normality. Further, WLS performed adequately only at the largest sample size but led to substantial estimation difficulties with smaller samples. Finally, robust WLS performed well across all conditions.(PsycINFO Database Record (c) 2019 APA, all rights reserved)
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