The purpose of this study is to explore the use of unfolding models for evaluating the quality of ratings obtained in rater-mediated assessments. Two different judgmental processes can be used to conceptualize ratings: impersonal judgments and personal preferences. Impersonal judgments are typically expected in rater-mediated assessments, and these ratings reflect a cumulative response process. However, raters may also be influenced by their personal preferences in providing ratings, and these ratings may reflect a noncumulative or unfolding response process. The goal of rater training in rater-mediated assessments is to stress impersonal judgments represented by scoring rubrics and to minimize the personal preferences that may represent construct-irrelevant variance in the assessment system. In this study, we explore the use of unfolding models as a framework for evaluating the quality of ratings in rater-mediated assessments. Data from a large-scale assessment of writing in the United States are used to illustrate our approach. The results suggest that unfolding models offer a useful way to evaluate rater-mediated assessments in order to initially explore the judgmental processes underlying the ratings. The data also indicate that there are significant relationships between some essay features (e.g., "word count," "syntactic simplicity," "word concreteness," and "verb cohesion") and essay orderings based on the personal preferences of raters. The implications of unfolding models for theory and practice in rater-mediated assessments are discussed.