Long-Term Effects of Collaborative Task Planning Vs. Individual Task Planning on Persian-Speaking Efl Learners’ Writing Performance

This study was aimed to compare longterm effects of collaborative and individual task planning on persianspeaking efl learners’ writing performance, using brown and bailey’s (1985) rating scale. therefore, a group of 90 upperintermediate efl learners in collaborative task planning, individual task planning, and control groups took part in the study. in the experimental groups, the participants were required to do task planning before attempting the main task. all the participants took a pretest, posttest, and delayed posttest. anova results indicated task planning produced better writing performance in the experimental groups on the posttest and delayed posttest. furthermore, repeated measures analyses showed both time and group played a part in the efficacy of the treatment. in fact, the participants of the experimental groups continued to retain the effects of task planning. results provide further support for the sociocultural theories of l2 development, according to which learning can be strengthened interpersonally.