<p>Unit-weight sum scores (UWSSs) are routinely used as estimates
of factor scores on the basis of solutions obtained with the non-linear exploratory
factor analysis (EFA) model for ordered-categorical responses. Theoretically, this
practice results in a loss of information and accuracy, and is expected to lead
to biased estimates. However, the practical relevance of these limitations is far
from clear. In this article we adopt an empirical view, and propose indices and
procedures (some of them new) for assessing the appropriateness of UWSSs in non-linear
EFA applications. A new automated approach for obtaining UWSSs that maximize fidelity
and correlational accuracy is proposed. The appropriateness of UWSSs under different
conditions and the behavior of the present proposal in comparison with other
more common approaches are assessed with a simulation study. A tutorial for interested
practitioners is presented using an illustrative example based on a well-known personality
questionnaire. All the procedures proposed in the article have been implemented
in a well-known noncommercial EFA program. </p>
The appropriateness of sum scores as estimates of factor scores in the multiple factor analysis of ordered-categorical responses.
