Validating human and automated scoring of essays against “True” scores

In the current study, two pools of 250 essays, all written as a response to the same prompt, were rated by two groups of raters (14 or 15 raters per group), thereby providing an approximation to the essay’s true score. An automated essay scoring (AES) system was trained on the datasets and then scored the essays using a cross-validation scheme. By eliminating one, two, or three raters at a time, and by calculating an estimate of the true scores using the remaining raters, an independent criterion against which to judge the validity of the human raters and that of the AES system, as well as the interrater reliability was produced. The results of the study indicated that the automated scores correlate with human scores to the same degree as human raters correlate with each other. However, the findings regarding the validity of the ratings support a claim that the reliability and validity of AES diverge: although the AES scoring is, naturally, more consistent than the human ratings, it is less valid.