As one of the viable and alluring technological devices, mobile devices have become widely available and advocated in educational settings (Looi et al., 2010; Wang et al., 2017; Hwang and Fu, 2018; Liu et al., 2018; Rassaei, 2019; Fathi et al., 2021). Mobile learning refers to the use of mobile technologies, such as smartphones and tablets (Huang et al., 2016), for educational purposes. Mobile-based learning is considered “learning across multiple contexts, through social and content interactions, using personal electronic devices” (Crompton, 2013, p. 4). In contrast to conventional computer-based learning technologies, which are constrained by time and place, mobile-based technologies provide their users with ubiquitous access that is not constrained by spatial and temporal factors (Kukulska-Hulme and Traxler, 2005; Melhuish and Fallon, 2010; Wong, 2012; Wang and Shih, 2015). That is, the mobility of mobile-based technologies, like mobile phones, iPod, and tablets, provide second language (L2) learners with a convenient place and time and great learning opportunities (Sharples, 2006; Laurillard, 2007), which might not be supplied by desktop computers (Chinnery, 2006).

In line with mainstream education, the use of mobiles in language learning, or what is currently known as mobile-assisted language learning (MALL), gained much popularity (Kiernan and Aizawa, 2004; Hwang and Fu, 2018), as it was included in the foreign language curriculum and offering new learning devices to the net generation (Oblinger and Oblinger, 2005). MALL has received much interest because of its authentic and contextual language learning experiences (Chinnery, 2006; Kukulska-Hulme, 2006; Shadiev et al., 2017; Cheng and Chen, 2022). Previous research on MALL has examined the effect of mobile-based technologies on EFL learners’ language learning skills, such as speaking (Sun et al., 2017), writing (Eubanks et al., 2018), listening (Jia and Hew, 2019), and reading (Chang and Hsu, 2011), and language sub-skills, such as grammar (Chu et al., 2019), vocabulary (Çakmak and Erçetin, 2018), and pronunciation (Wongsuriya, 2020). In comparison with all the MALL-related studies, the effect of mobile devices on vocabulary learning has attracted the most attention (Burston, 2014; Duman et al., 2015).

Although the impact of mobile-based technologies on English language vocabulary learning has been explored extensively (Stockwell, 2010; Çetinkaya and Sütçü, 2018; Lin and Lin, 2019), no large-scale studies have been carried out so far to check the potential impact of MALL on vocabulary learning attitudes in an EFL context. Following Masgoret and Gardner (2003), vocabulary learning attitude could be conceptualised as learners’ positive/negative reactions towards their vocabulary learning. Positive attitudes towards second/foreign language learning (in this study, positive attitudes towards vocabulary learning) enhance learners’ second/foreign language learning motivation and help them easily accomplish their language learning tasks (Ellis, 2008; Cheung and Hew, 2009; Nation and Webb, 2011; Burston, 2015; Chen et al., 2020; Soyoof et al., 2021, 2022). Therefore, positive attitudes towards vocabulary learning can facilitate second/foreign language learners’ vocabulary learning.

The present study, therefore, is aimed to examine the influence of a 1-year MALL programme on EFL learners’ vocabulary learning attitudes. That is, a quantitative longitudinal research design is adopted in this study to investigate EFL learners’ longitudinal trajectories and patterns of change in vocabulary learning. In addition, as the concept of self-regulation (Zimmerman and Schunk, 2008), which refers to learners’ activating and sustaining planned self-generated thoughts, emotions, and activities to achive their learning goals (Zimmerman, 2000, 2008), has received considerable attention in the MALL context (e.g., García Botero et al., 2021), especially in mobile-based vocabulary learning context (e.g., Barth et al., 2020). EFL learners’ self-regulatory vocabulary learning changes over the 1-year MALL programme is also examined in the present study. Moreover, the reciprocity and relationship between EFL learners’ vocabulary learning attitudes and their self-regulatory vocabulary learning are checked in this study.

As Engeström’s (1987) activity theory, which was adopted in the current study, explores learners’ gradual movement from other-regulation (i.e., interactive activities among peers) to self-regulation (i.e., learners’ autonomous functioning), we investigated the EFL learners’ self-regulatory vocabulary learning to check if EFL learners reach their self-regulation in vocabulary lrarning. In addition, as collaborative activities among EFL learners occur infrequently in the current study on the one hand, and EFL learners rarely use mobile-based applications for their English language courses, exploring the EFL learners’ vocabulary learning attitudes in this new learning environment could shed more light on the related literature. Thefindings of the study can add to the literature given that no quantitative longitudinal growth modelling analysis has been carried out examining learners’ vocabulary learning attitudes and self-regulation in the EFL context. The findings of the present study can also propose practical implications to contribute to EFL learners’ vocabulary learning attitudes and their self-regulatory vocabulary learning in a mobile-based vocabulary learning context.

The theoretical framework of the present study follows Engeström’s (1987) activity theory. This theory originates from Vygotsky’s (1978) social constructivism in which learners’ self-regulation (i.e., internalisation of different skills) precedes their other-regulation (i.e., interactions and mediations among peers). Vygotsky’s (1978) conceptualisation of learning comprises three components of subject (e.g., EFL learners and teachers), object or the desired goals that the learners want to achieve by the activity (e.g., improvements in vocabulary learning), and the mediational tools or artefacts (e.g., online applications) that mediate between the subject and object (see, for instance; Ebadi and Rahimi, 2019; Fathi and Rahimi, 2020; Rahimi and Fathi, 2021). However, activity theory conceptualises learning as interactions among the subject, object, and artefact, rules or norms (e.g., using mobile devices), community to which learners share a common goal (e.g., class and institution), and division of labor which refers to learners’ responsibilities in accomplishing an activity in the community (e.g., instructors teaching EFL vocabulary and learners learning EFL vocabulary; Engeström, 2001). Based on this theory, learning could be regarded as an activity system in which learners are mediated by the tools to construct knowledge. Overtime, learners are expected to internalise the knowledge and act autonomously without receiving mediations from the other capable individuals and achieve their self-regulation.

The conceptualisation of activity theory is similar to the Vygotskyan constructivist theory used in Ebadi and Rahimi (2017, 2018, 2019), Rassaei’s (2020), and Rahimi and Fathi (2021) study, as students are involved in collaborative activities to provide and receive both explicit and implicit mediations. In such collaborative activities, students gradually provide more explicit mediations on their peers’ tasks only if the peers are not able to address their language issues through more implicit mediations. Students who address their language issues through minimal or implicit peer mediations are believed to be closer to their self-regulation in learning. However, activity theory goes beyond the Vygotsky’s social constructivist theory by considering not only the students, their peer mediations, and their language learning goals, but also the rules or norms that the students are required to consider, like applying special language learning tools, the context where the students are engaged in the collaborative language learning activities, such as classroom context, and the students’ responsibilities to do the target activity, like learning EFL vocabulary. That is, activity theory considers a wider range of factors while specifically focusing on students’ collaborative learning activites.

Activity theory fits well with MALL desin and, in particular, with mobile-based vocabulary learning, since it can “capture the dynamic nature of activity systems and changing points of focus over time” (Levy and Stockwell, 2006, p. 119). On the other hand, as mobile-based learning is an activity that happens in the physical and social environments (i.e., interactions among learners and the community, rules, and norms of the activities) of learning, it corresponds to the principles of activity theory (Wali et al., 2008). Moreover, a number of studies have adopted activity theory in mobile-based language learning environment (e.g., Uden, 2007; Liaw et al., 2010).

Following this theory, the EFL learners in the present study are mediated by their peers and the researcher/instructor to accomplish the vocabulary-based activities in the mobile learning environment. The learners, considered the subjects in the activity theory, form the learning community, since they all follow a common goal (i.e., improving their vocabulary knowledge) by sharing the responsibilities among the members to accomplish vocabulary-based activities using mobile applications. In the current study, activity theory helped explore the interactions between learners and their social and cultural contexts comprehensively, identify the constraints in the EFL MALL context, and capture longitudinal changes (e.g., Ellis, 2015; Soyoof et al., 2021) in EFL vacobulary learning attitudes and self-regulatory capacity in vocabulary learning. Activity theory has not been adopted in similar studies; as a result, the current study is believed to shed light on the literature.

As the literature review revealed, mobile-based applications had positive effects on EFL vocabulary learning attitudes (Wu, 2015; Kurt and Bensen, 2017; Lin and Yu, 2017) and self-regulatory capacity in EFL vocabulary learning (Chen et al., 2008; Sha et al., 2012; Haq, 2019). However, vocabulary learning attitudes and self-regulatory capacity in vocabulary learning have not been explored in quantitative longitudinal research designs in EFL context (Zhang and Zou, 2020). Given the fact that L2 learning takes a long time, comprehensive understanding of L2 processes and changes should be investigated over time (Ortega and Byrnes, 2009). Therefore, we employed a quantitative longitudinal research design and adopted Engeström’s (1987) activity theory to examine the EFL learners’ longitudinal trajectories and patterns of change for vocabulary learning attitudes and self-regulatory capacity in vocabulary learning in a 1-year MALL programme. The reciprocity and relationship between these two factors were also examined. Employing quantitative longitudinal research designs have “several conceptual, methodological, and practical advantages and can stimulate the development and empirical examination of more complex questions and models concerning L2 development over time” (Barkaoui, 2014, p. 65). To accomplish the purposes of the study, the following research questions are formulated:

Drawing on Engeström’s (1987) activity theory, the current study was set to examine the impact of a MALL programme on EFL learners’ vocabulary learning attitudes and self-regulatory capacity in vocabulary learning through a quantitative longitudinal research design. Two latent change score models and their interrelations were tested in the present study: within-person changes of vocabulary learning attitudes and self-regulatory vocabulary learning and between-person differences (individual differences). First, the results of within-person differences revealed overall increase in both vocabulary learning attitudes and self-regulatory vocabulary learning. In other words, the involvement of learners in MALL activities contributed to positive vocabulary learning attitudes and self-regulatory capacity in vocabulary learning over time.

The results of the present study could be in line with the findings of Ellis (2008), Burston (2015), and Liu (2016) who confirmed the beneficial role of mobile-integrated language learning procedures in creating positive learning attitudes. Rachels and Rockinson-Szapkiw (2018) also argued that mobile-based instruction developed learners’ positive perceptions towards vocabulary learning. The findings of this study seem justifiable since mobile devices are likely to have provided the participants with collaborative activities both in and outside the classroom, thereby, contributing to foster positive learning attitudes among EFL learners. This means that the mobile applications possessed a lot of affordances for involving the learners in collaborative activities so that the learners could carry out the vocabulary tasks more conveniently and enthusiastically. In agreement with the findings, Lu (2008) also claims that MALL encourages interactions among the learners, enhances integrations among natural communication needs and language learning, and fosters retention of language learning skills.

Furthermore, following Engeström’s (1987) activity theory, the researcher/instructor’s and the other peers’ mediations engaged the learners in vocabulary-based activities. The instructor’s and other peers’ mediations along with the MALL environment helped the learners reach their self-regulation. Different applications available in the MALL space helped the learners have more effective and efficient peer mediations on each other’s communicative activities, which could further contributed to their vocabulary improvements. The findings of the present study showed that the MALL programme helped the EFL learners engage in other-regulation activites, following Engeström’s (1987) activity theory, as they were willing to use the MALL applications for vocabulary improvement purposes. The learners’ other regulations in the MALL environment also helped the learners reach their self-regulation in vocabulary development. That is, the learners gradually became autonomous in using the MALL applications appropriately for improving their vocabulary knowledge. This could be regarded as another evidence of the MALL learners’ high vocabulary improvements. The EFL learners also had more positive vocabulary learning attitudes which might further substantiate the above-mentioned findings of the study.

With regard to the improvements in self-regulatory vocabulary learning, the findings of the present study are consistent with those of Shea and Bidjerano (2010) and Lai and Gu (2011) who emphasised the effects of technological devices on fostering self-regulated learning. According to Zimmerman (2000), self-regulated learners are able to become meta-cognitively, motivationally, and behaviourally active participants of their own learning processes. From this perspective, the learners of the present study were meta-cognitively, motivationally, and behaviourally active in the sense that MALL helped them set more appropriate goals and use effective strategies to manage processes and content and to engage in help-seeking, self-monitoring, and self-evaluation. It could be argued that MALL marks a shift from teacher-driven learning to student-driven learning which might help students become autonomous and active learners, take the responsibility of their own learning, and be able to self-regulate their learning processes. In addition, as mobile vocabulary learning applications provide the language learners with the opportunity to “control their learning process, learn at their own pace and learn for their learning needs without being confined in fixed class schedules and physical settings” (Wang and Shih, 2015, p. 373), they enable learners to self-regulate their learning processes.

These findings are also consistent with Engeström’s (1987) activity theory, as learners self-regulation of learning is the desired outcome which they try to achieve following their interactions with other peers. Based on the Engeström’s (1987) activity theory, the MALL applications allowed the more capable peers to use self-regulatory strategies to mediate the less capable learners so that they could increase their vocabulary knowledge in the MALL environment more effectively. The community of more and less capable learners in the MALL environment allowed the less capable learners became more engaged in the communicative tasks as the capable peers were there to contribute to their vocabulary knowledge. These peer mediations between the less and more capable learners in the MALL space allowed both the more and less capable learners improve their vocabulary knowledge, and hence, their in self-regulatory vocabulary learning.

Between-person differences of change were also examined to address the second purpose of the present study. The interrelation of EFL vocabulary learning attitudes and self-regulatory capacity in vocabulary learning was investigated using bivariate change models in which each variable is considered a predictor for the other. The findings in this regard indicated that change in vocabulary learning attitudes and self-regulatory capacity in vocabulary learning was positively correlated. That is, EFL learners who showed high improvements in vocabulary learning attitudes were willing to show more self-regulatory capacity in vocabulary learning, whereas EFL learners who showed less improvements in vocabulary learning attitudes had a tendency to show less self-regulatory capacity in vocabulary learning. The reciprocal relationship between learning attitudes and self-regulated learning was corroborated by Zimmerman and Schunk (2008) and Ning and Downing (2010). These findings demonstrated that learners with positive learning attitudes were more likely to show self-regulatory and achievement-oriented behaviours. Based on activity theory (Engeström, 1987), learners who were actively engaged in vocabulary-based interactions in MALL environment (i.e., other-regulating their vocabulary knowledge) were better able to achieve their self-regulation of vocabulary learning.

The current study employed a dynamic rather than a static procedure to assess changes via latent change score models. This procedure helped identify model changes in EFL learners’ vocabulary learning attitudes and learners’ self-regulatory vocabulary learning, as well as their interrelation, allowing the investigation of within-person changes and between-person differences in change. However, the EFL learners’ vocabulary learning attitudes and self-regulatory vocabulary learning were measured through self-report scales. Moreover, since the changes in both variables were assessed simultaneously, causality inference in the relationship of the two variables changes were not possible. Given the fact that the present study utilised a two-wave set of data in the analysis, future EFL researchers are recommended to include more time waves and investigate more detailed analyses of change. Following Ellis (2015), in order to confirm changes in language acquisition, research data need to be based on learners’ social activities or participations and learners’ change in a particular and different context.

The current study showed the importance of MALL in fostering EFL learners’ vocabulary learning attitudes and self-regulatory capacity in vocabulary learning. With regard to the fruitful results of the present study, implications for EFL learners, teachers, and educators are suggested. For instance, the vital role of MALL in enhancing EFL learners’ vocabulary learning attitudes and regulating their English vocabulary learning were confirmed in the present study, although some learners did not consider MALL efficient in regulating their vocabulary knowledge. The insular learners changed their mind about efficiency of MALL in boosting their vocabulary knowledge, as they found themselves enriched in pervasive domination of vocabulary at the end of the course due to using numerous mobile applications.

Not only language learners, but also EFL teachers can benefit from the findings of the present study. For instance, they may enjoy mobile-based applications to support the teaching process. To this aim, EFL teachers need to be equipped with a pre-packed collection of mobile applications appropriate for theirlanguage teaching and learning context. The results of this study further encourage EFL teachers not to see mobile phones as an interruptive device in EFL education contexts but rather as a great facilitator of English vocabulary learning in classroom. It is also implied that mobile-based applications facilitate both learner-learner and learner-teacher interactions. Çetinkaya and Sütçü (2018), in this regard, argue that mobile-based applications help learners have more in-class and out-of-class interactions. Moreover, Çetinkaya and Sütçü (2018) claim that mobile applications expedite the question-and-answer interplay between learners and teachers. Following the findings of the current study, EFL teacher educators and policy makers might provide and facilitate a convenient condition for EFL teachers and learners to apply such mobile-based applications in their vocabulary learning courses.

Additionally, incorporating mobile-based applications for improving the vocabulary knowledge of EFL learners, enhances both learner-learner and instructor-learners interactions during and outside the class. EFL learners can have and receive more peer- and instructor- vocabulary mediations and improve their vocabulary knowledge in that regard (Rassaei, 2020). Incorporating mobile-based applications can also increase EFL learners’ motivation, which can help them enhance their vocabulary knowledge and self-regulatory vocabulary learning. However, it is important to instruct EFL instructors to incorporate appropriate mobile-based applications in their EFL courses. EFL learners need to be familiarised with the mobile-based applications, so as to apply the applications not only when they are engaged in collaborative activities with their peers, but also when they use the applications autonomousely (when they achieve their self-regulation in vocabulary learning), like those of Rahimi and Fathi (2021) and Rassaei’s (2021) study in which learners achieved their self-regulation after providing and receiving implicit and explicit peer mediations. Following Simpson (2005), getting an acceptable level of digital literacy seems to be a fundamental prerequisite to conduct mobile-based courses in EFL contexts. Digital literacy could be defined as “the ability to use information and communication technologies to find, evaluate, create, and communicate information, requiring both cognitive and technical skills” (Digital Literacy Task Force, 2013, p. 2). Therefore, increasing EFL learners’ digital literacy might further help the learners perform better in mobile-based vocabulary learning environments.

However, the findings of this study need to be generalised with caution as it was conducted among specific participants in EFL setting. Additionally, due to learner differences in cognition and English proficiency level, which could probably affect the way the learners in the present study were engaged in the mobile-based environments, the EFL researchers are recommended to consider more in-depth studies about EFL learners with similar cognition and English proficiency level. It is also worthwhile to propose that neither superiority nor priority of any special kind of mobile phone was taken into consideration during this study. And even the practicality and applicability of mobile phones over other mobile technologies, such as PDAs, iPads, or tablets, were not regarded as the vital emphasis of this study.

Furthermore, as we could not make sure if the participants used the applications consistently and if they did not involve in other modes of learning, other researchers might carry out a similar study and adopt an online programme and instrument to check and record EFL learners’ use of the applications. This could be controlled somehow, but as the nature of the longitudinal study, other factors might be involved affecting learners’ improvement in a long period of time which cannot be controlled completely. Moreover, as we only used one group of learners, other researchers may add a control group of learners who do not use mobile based applications to make a comparison between the experimental and control groups’ vocabulary learning attitudes and self-regulatory capacity in vocabulary learning so that the findings could be generalised and more valid.

In the Iranian context, on the other hand, vocabulary is usually decontextualised and taught as a separate skill. As a result, EFL learners do not usually find opportunities to use the words in their speaking and writing activities. That is, following Li and Hafner (2022), instructors in the EFL contexts only try to enhance EFL learners’ receptive knowledge of vocabulary by teaching vocabularies individually or through listening and reading skills; however, instructors ignore EFL learners productive knowledge of vocabulary. This means that in the EFL contexts, learners are not usually involved in speaking and writing activities to use their vocabulary knowledge productively. As the current study indicated, mobile-based applications provide a user-friendly and convenient online environment for EFL student not only to improve their receptive knowledge of vocabulary, but also to apply their newly acquire vocabularies productively through collaborative activities with their peers.

The data analyzed in this study is subject to the following licenses/restrictions: the dataset will be available upon request by contacting the corresponding author. Requests to access these datasets should be directed to jfathi13@yahoo.com.

The studies involving human participants were reviewed and approved by University of Kurdistan. The patients/participants provided their written informed consent to participate in this study.

All authors have contributed equally to data collection, data analysis, research questions, topic development, writing the manuscript as well as its revision, and language editing.

This paper was supported by Blended Learning Design and Practice of EFL Courses based on BOPPPS and an APP Named Chaoxing Learning (ZH202138), A Research on the Teaching Effect Evaluation of Ideological and Political Education in Medical Humanities (2021RWJD01SZ), and A Research on the Teaching Design and Application of Undergraduate Dissertations in English Majors (202102431018).

The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher.