“…Previous studies (e.g., Adodo & Agbayewa, 2011;Fauziah & Latief, 2016;Maftoon & Ghafoori, 2009;Zamani, 2016) on pair collaborative writing have concentrated on two separated areas, experimental studies on the effect of proficiency pairings on the EFL students' writing ability and descriptive studies on the collaborative process that occurs as observed through the verbalization process. In relation to the first area, the findings of existing studies (e.g., Adodo & Agbayewa, 2011;Fauziah & Latief, 2016;Maftoon & Ghafoori, 2009;Zamani, 2016) have provided mixed conclusions and, therefore, created space for further investigation, notably using different research designs that could integrate both writing outcome (after intervention) and the pair writing process. The second area also needs more exploration since the previous studies (e.g., Kim & McDonough, 2008;Leeser, 2004;Niu et al, 2018;Storch & Aldosari, 2013;Watanabe & Swain, 2007) mostly compared the collaborative writing process between pair and individual writing in strictly controlled and free writing tasks.…”