Explaining ESL essay holistic scores: A multilevel modeling approach

Abstract

This study adopted a multilevel modeling (MLM) approach to examine the contribution of rater and essay factors to variability in ESL essay holistic scores. Previous research aiming to explain variability in essay holistic scores has focused on either rater or essay factors. The few studies that have examined the contribution of more than one factor to variability in essay scores relied on analytic techniques that do not reflect the nested structure of essay ratings. One goal for this article is to illustrate the use and potential contributions of MLM to research on essay score variability. The study included 31 experienced and 29 novice raters who each rated a set of essays holistically and analytically. Scores were analyzed using MLM to examine the associations between essay features and holistic scores and the impact of rater experience on both essay holistic scores and these associations. The experienced raters assigned lower scores and gave more importance to linguistic accuracy than did the novices. Novices gave more importance to argumentation and their scores exhibited more variability. The article concludes by highlighting the value of MLM in identifying and estimating the contributions of various individual, textual and contextual factors in the rating context to variability in ESL essay scores.