Azizeh Chalak - English Department, Khorasgan Branch, Islamic Azad University, Khorasgan, Iran
Ahmad Moinzadeh - Department of English Language Teaching, Faculty of Foreign Languages, Isfahan University, Isfahan, Iran.
Mojdeh Ghiasi - English Department, Khorasgan Branch, Islamic Azad University, Khorasgan, Iran

This study investigated the effects of Whatsapp collaborative writing groups on ESp students' writing performance. A total of 30 university ESP learners were involved in this study. The students were divided into two groups; control and experimental groups. Whatsapp, as the treatment in this study was compared to a conventional method; face-to-face in the collaborative writing activities. The comparison between face-to-face and Whatsapp collaborative writing groups were made in order to measure students‟ writing performance on the intervention based on Jacob‟s et al. (1981) ESL Composition Profile; content, organization, vocabulary, language us and mechanics. Before using this approach, a pre-test was administered to all students and based on the preliminary results; students were divided into Whatsapp and face-to-face collaborative writing groups. After using both approaches, a post-test was given to participants in both groups. After the post-test a questionnaire was given to the students in order to investigate the effect of Whatsapp on the attitudes of ESP vocabularies and expressions by the ESP learners . The data were then analyzed using inferential statistics; independent t-test and paired sample t-test. From the findings, it was found that participants in Whatsapp collaborative writing groups displayed slightly higher scores compared to face-to-face collaborative writing groups. However, the differences between Whatsapp and face-to-face collaborative writing groups were not significant in the post-test writing scores. When comparison was made within each group, this study found that there were significant differences for overall writing performance, content, organization, vocabulary, language use and mechanics. The results also indicated that the students had positive attitudes toward using whatsapp collaborative learning.

Collaborative Learnin, ESP cours, Whatsapp, Mobile Assisted Language Learning (MALL