Diagnostic assessment of writing: A comparison of two rating scales

Abstract

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 (Weigle, 2002). The aim of this study is to compare two rating scales for writing in an EAP context; one 'a priori' developed scale with less specific descriptors of the kind commonly used in proficiency tests and one empirically developed scale with detailed level descriptors. The validation process involved 10 trained raters applying both sets of descr..