“…Percentage of error free clauses Abdi et al, 2012;Ahmadian, 2011;Ahmadian &Tavakoli, 2010, 2014Bamanger & Gashan, 2015;BavaHarji et al, 2014;Bui, 2019;De Jong & Vercellotti, 2016;Foster & Sekhan, 1999Fujita, 2006;Inoue, 2016;Khaerudin, 2014;Khoram & Zhang, 2019;Qian, 2010;Rafie et al, 2015;Saeedi, 2015;Shafaei et al, 2013;Tavakoli et al, 2016;Thurman, 2008;Vercellotti, 2012Vercellotti, , 2015Yuan, 2001 Lexical complexity Lexical diversity. The review found that the type-token ratio was used by some researchers (Fujita, 2006;Thurman, 2008;Yuan, 2001;Yuan & Ellis, 2003).…”