Investigating the relationship among complexity, range, and strength of grammatical knowledge of EFL students

Assessment of grammatical knowledge is a rather neglected area of research in the field with many open questions (purpura, 2004). the present research incorporates recent proposals about the nature of grammatical development to create a framework consisting of dimensions of complexity, range and strength, and studies which dimension(s) can best predict the state of grammatical knowledge of efl students. to this end, the specifications of a test of grammatical knowledge were drafted and reviewed by a group of trained reviewers. the specifications were revised and the test was administered to 158 english learners with mixed proficiency levels. the items were analyzed using classical test theory and rasch model. the results of stepwise regression indicate that the model that best predicts grammatical knowledge of lower ability leaners includes range and strength, while for the higher level strength and complexity are the best predictors.