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.