A Two‐Facet Measurement Methodology for Assessing Item Parcels: An application to measuring political knowledge in secondary school

Abstract

Recent literature on parcel indicators in measurement models used in covariance structural modelling has mainly been concerned with statistical properties of parameter estimates. Less attention has been paid to measurement properties for inferring the assumed latent construct. The present study illustrates a two‐facet measurement model that considers items and parcels simultaneously to test whether the aggregated item parcel information can replace the disaggregated item information in representing the same latent construct. In particular, the two‐facet model tests the existence of unidimensionality in a two‐facet measurement design where items are nested within parcels. The present methodology emphasises the need for conceptually based parcels to facilitate interpretation of the latent construct. The methodology is applied to a multifaceted construct of political knowledge measured in a sample of secondary school students.