Paper—Mobile Learning in Higher Education: A Bibliometric Review Mobile Learning in Higher Education: A Bibliometric Review

Changing habits leads to changes in ways of learning and teaching. The widespread use of smartphones appears as an opportunity and at the same time as a need for adoption in higher education institutions. The purpose of this paper is to analyze the scientific production on mobile learning in higher education in journals indexed in Clarivate Analytics’ Web of Science and Elsevier’s Scopus. The sample was composed by 450 articles in total. The results obtained by bibliometric analysis showed that the publication rates continue to increase, in which journals they are published, which are the organizations and countries that publish the most, how the evolution of perspective has changed since 2010 and which are the most cited articles. We concluded that since mobile learning in higher education is a reality, there still seems to be a possibility for evolution in good quality publications. Keywords—Mobile learning; M-Learning; higher education; Bibliometrics; Data analysis

be utilized when laptop or fixed station computers are unavailable. In 2011, Alzaza and Yaakub [4] considered m-Learning as the next generation of e-Learning using mobile technologies. Bannan [5] said that Mobile learning has become a recognized sub-domain of technology-enhanced learning.
Baran [6] defines mobile learning using multiple terms "mobility (Sharples et al.  [7] defined m-learning as a learning strategy that provides students with the 21 st century learning capabilities in order to enable them to utilize a wide range of portable computing devices. These devices are connected via smart classroom network or the Internet to smart components or online interactive educational content and learning resources. This means that you can be connected with a learning environment that is controlled by the teacher (instructor) using the Learning Management System (LMS) or tools of Social Online Learning (SOL) that achieve a collaborative, interactive and innovative learning environment.
However, there continues to be a distinct lack of definitional clarity about mobile learningconceptualizations may vary greatly but research designs tend to focus on attempts to measure the efficacy of mobile device-based interventions in terms of attainment or achievement gains [4]. Viberg et al [8] argue that in order to fuse informal and formal learning, m-Learning designers need to offer clearer definitions of the concepts "formal" and "informal", considering m-Learning as a part of e-Learning. While mobile phones provide many of the benefits associated with 1:1 computing, they also share some of the same barriers which, according O'Bannon and Thomas [9], could be disruptive and a distraction. Some students use mobile phones for cheating, sexting, and cyberbullying.
Jui-Long Hung and Ke Zhang [10] conducted a study based on 119 journal articles from 2003 to 2008. They found that m-Learning articles increased from 8 in 2003 to 36 in 2008 and that the most popular domain in current was Effectiveness, Evaluation, and Personalized Systems. Wu, Wu, Chen, Kao, Lin and Huang [11] reviewed 164 mobile learning studies from 2003 to 2010. Their major findings include that most studies of mobile learning were focus is on effectiveness, followed by mobile learning system design. Surveys and experiments were used as the primary research methods. Greig Krull and Josep M Duart [12] made a study of 233 articles dated from 2011 to 2015 to identify emerging trends in mobile learning research in higher education. They found that m-Learning in higher education was a growing field as evidenced by the increasing variety of research topics, methods and researchers; the most common research topic was about enabling m-learning applications and systems. Christoph Pimmera, Magdalena Mateescub and Urs Gröhbiela [13] selected 36 studies identified as eligible for review (2000 to 2013) and found that the broad majority of mobile and ubiquitous learning studies showed positive effects. However, empirical evidence that would favour a broad application of mobile and ubiquitous learning in higher education settings is still limited. In addition, the expectation that mobile learning could transform higher education cannot be confirmed because the majority of the reviewed studies followed instructionist paradigms. Qing-KeFu and Gwo-Jen Hwang [14] made a study which reviewed the literature on mobile technology-supported collaborative learning from 2007 to 2016. They found that mobile collaborative learning is a rapidly growing research field and that it is important to reinforce the research on the process of learners' knowledge construction as well as their perceptions and behaviors in collaborative learning processes. Sönmez, A.; Göçmez, L.; Uygun, D. & Ataizi, M. [15] selected 11 studies between 2013 and 2017 to explained mostly used purposes on articles. They concluded that the most popular topics were learners' perceptions of mobile technologies and mlearning and students' acceptance of m-learning. Chiu-Lin Lai [16] review of the top 100 highly cited mobile learning papers mainly focused on comparing the different mobile learning modes to find more effective approaches for conducting mobile learning activities. He concludes that mobile learning places have changed from classrooms to real-world contexts and that the number of across-context studies is increasing.
All of these studies are important to give clues on how research in the area has been carried out and eventually to predict future. This study provides insights not previously identified or evaluated in such detail using bibliometric indicators since the first articles were published until the year 2019. Bibliometric analysis [17] is the quantitative study of bibliographic material: it provides a general picture of a research field that can be classified by papers, authors and journals. Bibliometric methods employ a quantitative approach for the description, evaluation, and monitoring of published research. These methods have the potential to introduce a systematic, transparent, and reproducible review process and thus improve the quality of reviews [18]. Bibliometric analysis provides objective criteria that can assess the research development in a field and act as a valuable tool for measuring scholarship quality and productivity [19]. Bibliometric methods offer systematization and replication processes that can improve understanding of the dissemination of knowledge in a field and can highlight gaps and opportunities that may contribute to the advancement of the discipline [20].
The aim of this study is to conduct a literature review of the Mobile Learning in Higher Education research using bibliometric methods. The next section presents the research questions. The methodology is defined in the third section. Then the results are presented and at the end they are discussed and the conclusion is made.

The Research Question
The question, along with the purpose of the review, the intended deliverables and the intended audience, determines how the data are identified, collected and presented [21]. There are several questions that we want to answer in this paper: • How has the evolution of the publication of articles in quality journals related to mobile learning in higher education been? • What are the characteristics of journals where there is a greater number of publications related to the subject? • What is the approach to m-Learning in higher education? Has it evolved over the years? • Who publishes on the subject?
• Where do researchers who are interested in m-Learning in higher education work?
What country do they live in? • What are the most cited articles? And in the last three years?

Methodology
The term bibliometrics was first used in 1969 by Alan Pritchard, hoping that the term would be used explicitly in all studies which seek to quantify the processes of written communication and would quickly gain acceptance in the field of information science [22]. Moed mentioned the potential of this type of study that reveals the enormous potential of quantitative, bibliometric analyses of the scholarly literature for a deeper understanding of scholarly activity and performance, and highlights their policy relevance. [23] In scientific research, it is important to get a wider perspective of research already being conducted concerning a relevant subject matter [24] and a bibliometric analysis profile on the research trajectory and dynamics of the research activities across the globe [25]. This is a bibliometric study that systematically analyses the literature using articles indexed at Elsevier's Scopus (Scopus) and Clarivate Analytics' Web of Science (WoS) databases. This study conducts a bibliometric analysis of international journal papers that we expect provides a useful reference for future research.
The search strategy was Title: "mobile learning" OR "m-Learning" OR M-Learning Title-Abstract-keywords: Univers* OR "higher education" DocType: Article OR Review PUBYEAR: <2020.

Results
A set of 306 published papers were collected from WoS and 441 from SCOPUS. The search returned a total of 450 articles and reviews after discounting the duplicate results. The first article in Scopus was published in 2007 (   In the 450 articles we found 3386 keywords (even through 18 of the articles do not have keywords). Mobile Learning (261)    iJIM -Vol. 14, No. 11, 2020 Considering only the address of the first author, the papers are from 64 countries. There are 15 countries that are responsible for at least ten papers. These 15 countries represent 70% of our 450 papers (  (10) and Oman (10).
Continuing to analyse only by the first author, we find that there are 5 organizations that stand out for the amount of articles: published three of these organizations are from Malaysia, one from Oman and the other from the Republic of Korea (Organizations with more references).  Since we had not used the language exclusion criterion, we can now see that English is used in 87% of the articles ( ). The other languages are Spanish 6%, Korean 4% and Portuguese 1%. In the following table (Most cited papers) we list top ten more cited papers.  H. Hamidi and A. Chavoshi; 2018; Analysis of the essential factors for the adoption of mobile learning in higher education: A case study of students of the University of Technology; Telematics and Informatics is the article with the highest annual average of citations (considering the year of publication). This paper, with a study of "what is the impact of the mobile phone usage in education?" provides approaches and theories on mobile learning in training. The paper aimed to evaluate the essential factors for the adoption and application of education information system that has been created by students. Furthermore, a case study from students of K. N. Toosi University in Iran was presented to indicate the performance of this method in practice. The statistical society included 300 members who were Information Technology students of Iran's K. N. Toosi University of Technology. The factors related to adoption of mobile learning in higher education were classified into seven main categories as: ease of use, trust, characters and personal qualities, context, perceived usefulness of using, behavioural intention, and culture of using a research model. From the results, one could perceive that mobile learning may be one of the promising educational technologies for development in educational environments and culture of using.
H S. S. Oyelere, J. Suhonen, G. M. Wajiga and E. Sutinen; 2018; Design, development, and evaluation of a mobile learning application for computing education;Education and Information Technologies; 23; 467-495 aims to evaluate MobileEdu in a real-life learning setting. An experiment was conducted with 142 third-year undergraduate students in a Nigerian university. Besides the learning achievement of the students using Mo-bileEdu, the study examined the impact of MobileEdu on students' attitudes toward studying in a system analysis and design course. Experimental data were collected from pre-and post quizzes, interviews, and a questionnaire was administered to students. The results of the evaluation are encouraging and showed that the MobileEdu application has a potential to improve students' learning achievements.
In the following table (Most cited papers 2017-2019) we list the most cited 2017-2019.

Discussion and Results
The purpose of this paper is to analyse the scientific production in mobile learning in higher education in journals indexed in Clarivate Analytics' Web of Science and Elsevier's Scopus. The sample was composed by 450 articles in total. Let us now answer the research questions: • How has the evolution of the publication of articles in quality journals related to mobile learning in higher education been? The results obtained by bibliometric analysis showed that publication rates continue to increase: Bibliometric results indicate that m-Learning in higher education is still a topic with a tendency to increase in number and quality of scientific production.