Investigating Writing Sub-skills in Testing English as a Foreign Language: A Structural Equation Modeling Study

This study investigates the validity of a writing model proposed as the underlying structure of the writing skill in English as a foreign language (EFL). Four writing prompts were administered to 178 Iranian EFL learners. The scripts were then scored according to writing benchmarks similar to the IELTS Writing criteria but narrower in scope. After interand intra-rater reliability analysis, a three-factor model was posited for validation. Structural modeling of the sub-skills revealed the two sub-skills of Idea Arrangement and Communicative Quality are psychometrically inseparable, but the Vocabulary and Grammar sub-skills proved to have good measurement properties. Using parcel indicators, a two-factor model was then evaluated which had the best fit and parsimony. The researcher concludes Idea Arrangement and Communicative Quality appear to have similar conceptual and theoretical foundations and should be considered the elements of one measuring criterion. Further research is required to support this finding. [1]