“…Some studies revealed that portfolio assessment has a significant impact on students' writing ability as well as their improvement in terms of content, organization, vocabulary, grammar, and mechanics (Efendi et al, 2017;Roohani & Taheri, 2015;Samad et al, 2017;Shokraie & Tabrizi, 2016;Tabatabaei & Assefi, 2012). The other findings found that portfolio assessment has a positive impact on students' writing performance in general and particularly in terms of content, organization, grammar, vocabulary, and mechanics (Obeiah & Bataineh, 2016;Prastikawati et al, 2016;Shokraie & Tabrizi, 2016;Tabatabaei & Assefi, 2012).…”