Differences in rater judgments that are systematically related to construct-irrelevant characteristics threaten the fairness of rater-mediated writing assessments. Accordingly, it is essential that researchers and practitioners examine the degree to which the psychometric quality of rater judgments is comparable across test-taker subgroups.…

Alderson (2005) suggests that diagnostic tests should identify strengths and weaknesses in learners' use of language and focus on specific elements rather than global abilities. However, rating scales used in performance assessment have been repeatedly criticized for being imprecise and therefore often resulting in holistic marking by raters…