The purpose of this study was to explore the nature of interactions among second/foreign language (L2) writing subskills. Two types of relationships were investigated: subskill-item and subskill-subskill relationships. To achieve the first purpose, using writing data obtained from the writing essays of 500 English as a foreign language (EFL)…

This study compares five cognitive diagnostic models in search of optimal one(s) for English as a Second Language grammar test data. Using a unified modeling framework that can represent specific models with proper constraints, the article first fit the full model (the log-linear cognitive diagnostic model, LCDM) and investigated which model…