The effects of group size on critical thinking and writing development in collaborative writing: A mixed methods study

In recent years, research on collaborative dialogue and peer interaction patterns in ESL/EFL collaborative writing (CW) and their relation to the co-constructed text quality has been burgeoning. However, scarce is the research on the interplay between CW and critical thinking (CT). This study employs a mixed-methods research (MMR) design, integrating a quasi-experimental study with focus group interviews, to examine the influence of CW group sizes on CT and writing proficiency among 184 intermediate EFL tertiary-level learners. The participants were divided into four experimental groups—pairs, triads, quads, and quintets—and a comparison group that engaged in independent writing. Over eight weeks, all groups completed pre- and post-tests in writing proficiency and produced two argumentative essays to assess CT skills. After the posttest, four focus group interview sessions were conducted, one for each of the four experimental groups. The quantitative results indicate a trade-off: larger CW groups cultivate collective CT but impair individual writing proficiency. The interview data reveal a different trade-off: despite their higher CT performance, larger groups may report more conflicts and less favorable perceptions of CW tasks in fostering CT. The study discusses the pedagogical implications of these findings and offers recommendations for optimizing CW group sizes to balance CT development with writing proficiency.