Table 3.

Key advantages of parcels vs. items

Psychometric Characteristics Parcels (as opposed to the items) have… Higher reliability Greater communality Higher ratio of common-to-unique factor variance Lower likelihood of distributional violations More, tighter, and more-equal intervals

Model Estimation and Fit Characteristics Models with parcels (as opposed to the items) have… Fewer parameter estimates Lower indicator-to-sample size ratio Lower likelihood of correlated residuals & dual factor loadings Reduced sources of sampling error

Note. These advantages pertain to the smaller set of parcels that are made up from a larger set of items. The advantages accrue based on the principle of aggregation and the law of large numbers.