Optimizing Rating Scales for Self-Efficacy (and Other) Research

This article (a) discusses the assumptions underlying the use of rating scales, (b) describes the use of information available within the context of Rasch measurement that may be useful for optimizing rating scales, and (c) demonstrates the process in two studies. Participants in the first study were 330 fourth- and fifth-grade students. Participants provided responses to the Index of Self-Efficacy for Writing. Based on category counts, average measures, thresholds and category fit statistics, the responses on the original 10-point scale were better represented by a 4-point scale. The modified 4-point scale was given to a replication sample of 668 fourth- and fifth-grade students. The rating scale structure was found to be congruent with the results from the first study. In addition, the item fit statistics and item hierarchy indicated the writing self-efficacy construct to be stable across the two samples. Combined, these results provide evidence for the generalizability of the findings and hence utility of this scale for use with samples of respondents from the same population.