This study investigated the effect of using a non-traditional writing task and different
audiences on 9th grade students’ conceptual understanding of a chemistry unit on mixture.
524 students instructed by 3 chemistry teachers in 2 public high schools participated in
this study. Upon completion of the mixture unit, 181 students engaged in traditional
writing activities, 121 students wrote a letter to a younger audience, 92 students wrote a
letter to their peers, and 130 students wrote a letter to their teacher. Mixture achievement
test was administered as a pre- and posttest to all the groups to assess students’
understanding of mixture concepts. Semi-structured interviews were conducted with 24
students from the non-traditional writing group at the end of the instruction to
understand students’ ideas about non-traditional writing task. Posttest analyses indicated
that non-traditional writing group outperformed the traditional writing group, and the
groups that wrote to peers and younger students performed better than those that wrote
to the teacher, when the effects of the pretest scores were controlled. The results also
showed that students’ performance on the writing task significantly differed with respect
to the audience. Moreover, interview results revealed that non-traditional writing tasks
were very helpful in students’ understanding of the mixture concepts.