RASCH RATING SCALE MODELING OF DATA FROM THE STANDARDIZED LETTER OF RECOMMENDATION

Abstract

The Standardized Letter of Recommendation (SLR), a 28-item form, was created by ETS to supplement the qualitative rating of graduate school applicants' nonacademic qualities with a quantitative approach. The purpose of this study was to evaluate the following psychometric properties of the SLR using the Rasch rating-scale model: dimensionality, reliability, item quality, and rating category effectiveness. Principal component and factor analyses were also conducted to examine the dimensionality of the SLR. Results revealed (a) two secondary factors underlay the data, along with a strong higher order factor, (b) item and person separation reliabilities were high, (c) noncognitive items tended to elicit higher endorsements than did cognitive items, and (d) a 5-point Likert scale functioned effectively. The psychometric properties of the SLR support the use of a composite score when reporting SLR scores and the utility of the SLR in higher education and in admissions.