“…Being an indispensable textual property, cohesion, the grammatical and lexical glue of discourse (Celce-Murcia, 1991), aids in the formation of textual/discourse competence (see, e.g., Bachman, 1990;Canale, 1983;Canale & Swain, 1980), the ability to handle language above the sentence or to structure a series of sentences as a meaningful whole, which has been increasingly deemed in the SLA field as one of the most important constituent abilities that contribute to a language learner's overall proficiency (e.g., Bachman & Palmer, 1982;Harley, Cummins, Swain, & Allen, 1990). In reality, textual/discourse competence has been valued over the production of basic intrasentential elements like vocabularies or isolated syntactic forms by researchers in recent L2 writing research (e.g., Chiang, 2003;Liu & Braine, 2005), given that becoming a competent user of a target language involves more than interiorizing its essential linguistic forms (Kang, 2005), e.g., vocabulary and grammar, and that only through the analysis of learners' output of the linguistic units beyond words and sentences can inquirers offer a valid and reliable portrait of whether and how the learners command the target language. In other words, analyzing L2 writers' change features in (incorrect) using cohesive agents at different proficiency levels can provide more informative insights into their strengths and weaknesses in their learner language variations, especially those at the textual level which may intently relate to the overall proficiency of their learner language.…”