Benefits of mobile instant messaging to develop ESL writing Alberto Andujar Department of Linguistics, University of Almería, Spain article info Article history: Received 2 June 2015 Received in revised form 8 July 2016 Accepted 11 July 2016 Available online xxx Keywords: Mobile instant messaging Chat-based conversation Second language writing Mobile assisted language learning Noticing Collaborative learning abstract This study investigated the benefits of Mobile Instant Messaging (MIM) through an analysis of grammatical, lexical and mechanical accuracy as well as syntactic complexity in second-language learners' writing. A WhatsApp group was created where 80 Spanish students taking a B1 English course participated in a daily interaction during six months. A quasi-experimental research design with an experimental and control group and a pre- post test was followed. Students were divided into two main groups according to treat- ment type with 40 students in each group. This research focused on the interaction in the application and attempted to measure, through a qualitative and quantitative analysis, the students' degree of writing development. The ratios of lexical, grammatical and mechan- ical errors as well as error-free clauses per clause and error-free T-unit per T-unit indicated significant differences between the control and experimental group in terms of accuracy. Nevertheless, measures of syntactic complexity together with lexical diversity were not conclusive as the independent parameters for syntactic complexity showed no significant differences between the two groups. WhatsApp constitutes a powerful educational tool to encourage second language interaction among participants and its tremendous potential to activate students' involvement remains one of the least exploited functionalities of mobile phones. © 2016 Elsevier Ltd. All rights reserved. 1. Introduction Mobile learning breaks temporal and spatial lines, placing educative resources at the service of the students. Through mobile phones, Internet users now have the possibility of accessing the Internet from different points, having access to the net from almost any place. However, although its importance as a research field is increasing rapidly, as reflected in the numerous research articles, conferences, seminars and workshops taking place all over the world (see Gülbahar, Jacobs, & K€ onig, 2015), several reviews (see Burston, 2014; Cobcroft, Towers, Smith, & Bruns, 2006; Trifonova, 2003) indicate that MALL remains marginal, as experiments and class trials carried out lack follow-up reports showing curricular integration. This study is based mainly on the need for extending research related to the use of Mobile Instant Messaging (MIM) in the English as a Second Language (ESL) classroom and its benefits. MIM is an asynchronous and synchronous communication tool that uses wireless networks and handheld devices, allowing students to hold conversations and exchanges (Dourando, Parker, & De la Harpe, 2007; Rambe & Bere, 2013). This type of messaging is characterized by instant delivery through a pop-up mechanism, a list of users, and a mechanism to indicate when they are available. At the same time, it allows access to diverse content, acquisition of specific data and information sharing among users. MIM constitutes one of the functionalities which holds great potential in a mobile phone; typed messages have evolved to become a new hybrid of spoken, written and E-mail address: aav447@ual.es. Contents lists available at ScienceDirect System journal homepage: www.elsevier.com/locate/system http://dx.doi.org/10.1016/j.system.2016.07.004 0346-251X/© 2016 Elsevier Ltd. All rights reserved. System xxx (2016) 1e14 Please cite this article in press as: Andujar, A., Benefits of mobile instant messaging to develop ESL writing, System (2016), http:// dx.doi.org/10.1016/j.system.2016.07.004