DOI:10.6129/CJP.201903_61(1).0002
Chinese Journal of Psychology 2019, Vol.61, No.1, 25-50

The Nature of Multidimensional Constructs Represented by Item Parcels in Structural Equation Modeling

You-Lin Chen（National Taiwan University）；Li-Jen Weng（National Taiwan University）

Abstract

Item parcels, represented as summation or average over items, can be used as indicators of latent variables in structural equation modeling (SEM). Little et al. (2013) and Cole et al. (2016) indicated that the nature of the multidimensional constructs represented by parcels can be different from that assumed by the researchers. Researchers should thus examine the nature of multidimensional constructs represented by parcels prior to the analysis. Cole et al. and Williams and O’Boyle (2008) pointed out that many constructs investigated in psychological research are multidimensional, consisting of several facets, and item parcels are frequently used as indicators for these constructs in SEM. The present study therefore extended the algebraic derivation of the covariance matrix of item parcels in Sterba & MacCallum (2010) from unidimensional to multidimensional constructs to provide a theoretical framework for examining the nature of multidimensional constructs implied by parcels. The effects of parceling strategy, correlations among facets, and factorial complexity of items on the nature of multidimensional constructs represented by parcels were discussed using this framework and illustrated with a numerical simulation example. Researchers are encouraged to apply the framework proposed in this study to clarify the nature of the multidimensional constructs inferred from item parcels by examining the covariance matrix among parcels to avoid misleading results from SEM analysis.

Keywords: item parcels, multidimensional constructs, structural equation modeling