With more than 1,200 publications over the past two decades, experimental mobile-assisted language learning (MALL) studies targeting second/foreign language (L2) acquisition outcomes are certainly not lacking in quantity. Their research quality, on the other hand, has often been brought into question, most notably with regard to the adequacy of their assessment instruments and statistical analyses. Yet limiting the determination of research quality to the evaluation of testing procedures, and the statistical analysis of the results they produce, ignores the critical relevance of the underlying research parameters that generate the results in the first place. A comprehensive evaluation of quantitative experimental L2 acquisition MALL research quality, encompassing design as well as assessment instruments and statistical analysis, thus remains to be undertaken. The present investigation endeavors to do so based on an extensive compilation of 737 MALL studies published between 2000 and 2021. The research quality of these publications is evaluated according to four main parameters: language acquisition moderators, treatment intervention conditions, assessment instruments, and statistical analysis. These are applied according to a modified version of the Checklist for the Rigor of Education-Experiment Designs (CREED), which classifies research design quality into five levels: low, medium-low, medium, medium-high, high. With over three quarters of all studies falling within the low category, the result leaves much to be desired. Since the modified CREED algorithm developed here can equally be applied to studies from their inception, it offers a way forward to improve the research quality of future experimental MALL studies.

It is usually the case that learners of English as a foreign language (EFL) are exposed to language materials in class only, and of course in such a short space of time, they do not always find enough chance to practice English grammar features and become aware of their grammar mistakes. As a potential solution to this problem, the current study inspects the impact of using cell phones, specifically text messages (via short message service) as supplementary tools, on Iranian elementary level EFL learners’ grammar learning. In the first phase of the study, 60 students aged 14 were randomly divided into experimental and comparison groups. Throughout the 12 weeks of treatment, the participants in the experimental group received 120 text messages containing grammar exercises, whereas the participants in the comparison group received a similar number of vocabulary messages as a placebo treatment and were otherwise treated exactly the same as the experimental group. A researcher-made grammar test was used to estimate whether presenting grammar exercises via text messages has any impact on language learners’ grammar learning. The results demonstrated that there was a significant difference (p<0.05) in the grammar learning of the participants who practiced grammar points through text messages and those who did not. The researchers also interviewed various stakeholders, comprising ten students, five parents, the teacher, and the school principal. A qualitative content analysis was carried out to find themes relevant to the stakeholders’ beliefs about making use of text messages for learning grammar. The findings suggest that text messages can be useful for learning grammar points, since they engage learners’ interest and encourage them to study more in order to text the correct answers when they are outside their classrooms.