A Systematic Review of the Beneﬁts and Challenges of Mobile Learning during the COVID-19 Pandemic

: Following the COVID-19 outbreak, teaching and learning have been forced to move fully to the Internet rather than the conventional ofﬂine medium. As a result, the use of M-learning has risen dramatically, which was neither expected or anticipated. The challenges and beneﬁts of such widespread usage are beginning to emerge in front of us. Thus, in this paper, we systematically review the beneﬁts and challenges of leveraging M-learning for Science and Technology courses during the COVID-19 pandemic by educators and learners. Related articles were obtained from various databases, namely, IEEE, ACM Digital Library, ScienceDirect, and Springer. In total, 4210 related articles were initially found. Upon executing careful selection criteria, 22 articles were selected for review. After that, the advantages and threats were identiﬁed and discussed. As per our ﬁndings, it was determined that M-learning has excellent potential to be an effective platform for education provided that the identiﬁed shortcomings are resolved. This review will be helpful for education stakeholders and institutions to gauge the impact of leveraging M-learning as the only means for education to proceed. Moreover, it reveals the strengths and shortcomings that would aid in adjusting the relevant policies administered by the institutions. Furthermore, application developers will be able to comprehend the expected features that should be included in novel M-learning platforms.


Introduction
Online learning, i.e., learning conducted through the Internet, has grown in popularity to the point where it is now offered in brick-and-mortar institutions that formerly solely offered face-to-face learning. Mobile learning (also known as M-learning) can be considered a subdivision of online learning, which refers to the process of learning across various settings through social and content exchanges through mobile devices such laptops, smartphones, and wearable technology [1,2]. It is a kind of remote education where learners use instructional technologies on mobile devices at their convenience [3]. The use of M-learning to promote teaching and learning among learners at the tertiary level has continued to be of interest. While M-learning is quickly seen as an efficient means of improving education, it must continue to evolve to meet today's learners' changing needs and learning demands [4]. Conventional ways of teaching and learning are no longer applicable and practical. Remote learning, flexibility, a user-friendly learning path, cost-effectiveness, and preparation for the digital future are some of the characteristics that distinguish mobile learning from traditional educational and training models [5].
Coronavirus disease 2019 (COVID- 19), which was first reported in the Hubei Province of the People's Republic of China, has easily spread across the world [6,7], infecting a large Section 6 concludes the paper.

Methods
The PRISMA methodology is one of the recommended procedures for systematic reviews [27]. This technique enables the development of a systematic strategy for locating relevant research [28]. The detailed procedure followed in conducting the review is illustrated in Figure 1.
For this study, the articles were obtained from four different databases: IEEE, ACM Digital Library, ScienceDirect, and Springer. The search string was the same for the four databases: {M-learning} OR {Mobile Learning} AND filter year within 2020 to 2021. Mainly, the search was carried out during the COVID-19 outbreak, which was from 2020 to 2021.
The inclusion criteria for this review were articles (i) involving M-learning for education and (ii) focused on Science and Technology courses. The exclusion criteria were articles that (i) concentrated on learners or educators below higher school, (ii) mainly emphasized the technical implementation of M-learning, and (iii) that were not published in English. In total, 4210 were found across four databases. Specifically, 1952, 656, 271, and 1331 articles were retrieved from the IEEE, ACM Digital Library, Springer, and ScienceDirect, respectively. The titles of the articles were then skimmed through, and 209 articles were For this study, the articles were obtained from four different databases: IEEE, ACM Digital Library, ScienceDirect, and Springer. The search string was the same for the four databases: {M-learning} OR {Mobile Learning} AND filter year within 2020 to 2021. Mainly, the search was carried out during the COVID-19 outbreak, which was from 2020 to 2021.
The inclusion criteria for this review were articles (i) involving M-learning for education and (ii) focused on Science and Technology courses. The exclusion criteria were articles that (i) concentrated on learners or educators below higher school, (ii) mainly emphasized the technical implementation of M-learning, and (iii) that were not published in English.
In total, 4210 were found across four databases. Specifically, 1952, 656, 271, and 1331 articles were retrieved from the IEEE, ACM Digital Library, Springer, and ScienceDirect, respectively. The titles of the articles were then skimmed through, and 209 articles were selected based on relevance, with 107 from IEEE, 28 from ACM Digital Library, 59 from Springer, and 12 from ScienceDirect. Subsequently, reading through the abstract, 62 articles were selected for further analysis. Only articles that were examined during the pandemic period with a focus on Science and Technology were chosen from the M-learning articles.
Finally, after reading the whole article and focusing on the inclusion criteria, a subset of articles was chosen, and the others were eliminated. To proceed, a total of 22 articles were included in the review.

Review of the Benefits and Challenges of M-Learning during COVID-19 Pandemic
The 22 selected articles that met the inclusion criteria were reviewed individually, and the results are presented in Table 1. In addition, the reference number with title, the methodology used by the researchers, the benefits and challenges of M-learning, the platform used, and the targeted audience, including significant findings of the respective research, were also provided in the same table.   New challenges for teacher education introduced by the use of ICT in the classrooms [45] Qualitative

Challenges:
Educators lack skills on the online platform as well as in assessment strategies.

Not mentioned Educators
Educators should be provided with guidance and training on preparing online courses and exams.
Teachers' adaptation to technologies during the pandemic by COVID-19 [46] Qualitative

Challenges:
Lack of adaptation and interaction between learners and educators.
Google Forms, PowerPoint, Prezi, Zoom High school learners and educators of Portugal As a consequence of the online platform, there is a lack of interaction and connection between learners and learners.
Impact of COVID-19 and "Emergency Remote Teaching" on the UK Computer Science Education Community [47] Mixed methods

Challenges:
Issues with assessment and examination.

Not mentioned Computer science learners
Due to the evaluation problem, and a dearth of practicum opportunities, the quality of online instruction is compromised as compared to face-to-face instruction. As shown in Table 1, it is noted that 11 articles discussed the benefits of M-learning, 15 articles focused on the challenges of using M-learning, and only 5 of them covered both aspects. Eighteen articles targeted learners, five targeted educators, and two articles targeted both groups. Engineering learners are the most popular group covered. Among these learners, computer science engineering learners were the highest. Several articles focused on the geographical location, the challenges, and benefits depending on the Educ. Sci. 2021, 11, 459 7 of 14 location, culture, and economy. Furthermore, 12 articles followed a qualitative method, 7 articles used a quantitative method, and 2 articles used a mixed-methods approach.
As per the objective of this review, we aim to assess the advantages and disadvantages of M-learning. The evident pros and difficulties were identified. The most significant benefits of M-learning, as stated in Table 1, are its mobility and flexibility. Aside from that, organized content is another significant benefit of M-learning. The most prevalent drawbacks are content issues, lacking connection, and lacking laboratory facilities. Moreover, several different platforms were mentioned, with Moodle, Zoom, Google Meet, and YouTube being the most common platforms. Figure 2 illustrates the proportion of evaluated papers classified according to their advantages, difficulties, and both. [49] As shown in Table 1, it is noted that 11 articles discussed the benefits of M-learning, 15 articles focused on the challenges of using M-learning, and only 5 of them covered both aspects. Eighteen articles targeted learners, five targeted educators, and two articles targeted both groups. Engineering learners are the most popular group covered. Among these learners, computer science engineering learners were the highest. Several articles focused on the geographical location, the challenges, and benefits depending on the location, culture, and economy. Furthermore, 12 articles followed a qualitative method, 7 articles used a quantitative method, and 2 articles used a mixed-methods approach.
As per the objective of this review, we aim to assess the advantages and disadvantages of M-learning. The evident pros and difficulties were identified. The most significant benefits of M-learning, as stated in Table 1, are its mobility and flexibility. Aside from that, organized content is another significant benefit of M-learning. The most prevalent drawbacks are content issues, lacking connection, and lacking laboratory facilities. Moreover, several different platforms were mentioned, with Moodle, Zoom, Google Meet, and YouTube being the most common platforms. Figure 2 illustrates the proportion of evaluated papers classified according to their advantages, difficulties, and both.

Discussion
This section discusses the benefits and challenges of adopting M-learning in Science and Technology courses.

Benefits
To avoid contracting COVID-19, the first and most important precaution is to keep a safe distance [50]. Globally, most educational institutions have embraced distant learning Challenges 48% Benefits 36% Both 16%

Reviewed paper which described
Challenges Benefits Both Figure 2. Percentage of the articles reviewed based on categories: benefits, challenges, and both.

Discussion
This section discusses the benefits and challenges of adopting M-learning in Science and Technology courses.

Benefits
To avoid contracting COVID-19, the first and most important precaution is to keep a safe distance [50]. Globally, most educational institutions have embraced distant learning education through M-learning. Learners are not required to attend face-to-face lectures, but rather attend courses online. M-learning aids in the prevention of the further spread of COVID-19 in schools, colleges, and institutions [29]. Stability and adaptability were the most often cited characteristics in the examined publications [36]. M-learning allows learners and educators to continue their education from any location. They save a lot of time because they do not need to commute to campus for lectures [39]. Furthermore, it allowed learners to study on their own time. Learners and educators can complete their teaching and learning tasks at any time from any location. M-learning makes lessons and class materials available online and offline, too, via a variety of platforms, including Padlet, Google Classroom, Google Meet, Moodle, Concept Warehouse, and YouTube videos [21,39]. A large number of people can take the same course at the same time through online education, whereas offline courses are confined to a fixed number [36]. When comparing the two methods of learning, online is preferable for dealing with a large number of students, provided the course is well-designed [24,36]. The most significant feature of M-learning is its mobility and flexibility, which contributed to its popularity in the world.
The content of education is crucial. Lectures, class materials, sample questions, and other educational resources should all be available through the online education system. Conducting the course is impractical without the appropriate resources. Before the epidemic, online education was not extensively utilized [51]. Now, it is a prevalent and widely used platform. To organize learning materials, it is suggested to use a learning management system. Educators can easily import all materials into the system according to courses and monitor the usage by learners easily [35].
Inventory costs, such as electricity bills and transportation, have dropped significantly since the schools closed and online education took over. The maximum number of students per class was also noted to increase. Simulated labs enable many learners to engage concurrently in a session [48]. Furthermore, learners are more likely to attempt a task many times if they fail the first time, allowing them to expand their horizons. Transitioning from conventional to completely mobile learning is a cost-effective strategy for institutions. When built properly, particularly for Science and Technology courses, online lab facilities would enable learners to do practical work at their own pace from any location [30].
Educators can engage students' attention via the use of a variety of online tools and apps, including Kahoot, Socrative, and Mentimeter. These often encourage learners to pay attention during the lesson [41]. In contrast to in-person assessments, which make it harder to identify cheating, online exams enable instructors to detect plagiarism via the use of applications such as Turnitin, Unicheck, and PlagScan. These practices assist learners in retaining their uniqueness and developing their intellect, innovation, and dynamism, while also benefitting the institution's budget due to the absence of paperwork in the assessment [43].

Challenges
Resource problems include content issues, offline versions of content and appraisal used for online modes, and a lack of knowledge in using the system. The resources required for online learning should be available. If the required resources, content, or material are available, M-learning would deemed be successful. These resources are dependent on the medium of instruction, whether online or offline (traditional) [33]. Therefore, they should be altered based on the medium of instruction. For example, due to COVID-19, learning institutions abruptly had to go online, with content prepared for traditional faceto-face classes [38]. Moreover, some of the existing content is not suitable for conducting online education. It can be challenging to develop content for online teaching mode due to lacking knowledge, structure, skills, and location as the opportunities are not the same in different parts of the world [42]. Furthermore, the platform used for M-learning should be designed to support a large number of users. Increased user traffic may affect the delivery of online education.
Life has improved drastically due to recent technological advancements [52], but people may find it hard to deal with age. Aged educators and learners do experience challenges in adapting to M-learning technology [31]. Non-ICT educators and learners find it

Challenges
Resource problems include content issues, offline versions of content and appraisal used for online modes, and a lack of knowledge in using the system. The resources required for online learning should be available. If the required resources, content, or material are available, M-learning would deemed be successful. These resources are dependent on the medium of instruction, whether online or offline (traditional) [33]. Therefore, they should be altered based on the medium of instruction. For example, due to COVID-19, learning institutions abruptly had to go online, with content prepared for traditional faceto-face classes [38]. Moreover, some of the existing content is not suitable for conducting online education. It can be challenging to develop content for online teaching mode due to lacking knowledge, structure, skills, and location as the opportunities are not the same in different parts of the world [42]. Furthermore, the platform used for M-learning should be designed to support a large number of users. Increased user traffic may affect the delivery of online education.
Life has improved drastically due to recent technological advancements [52], but people may find it hard to deal with age. Aged educators and learners do experience challenges in adapting to M-learning technology [31]. Non-ICT educators and learners find it harder to adjust to the latest online learning without proper hands-on training [39]. Furthermore, many educators find it challenging to teach entirely online. Preparing materials for M-learning is time-consuming and complicated [45].
Communication plays a vital role in the education system. It is challenging to execute teaching and learning activities without face-to-face contact between learners and educators [53]. Moreover, the platforms used for online education are not always effective in maintaining contact between them [44]. All are expected to conform to this new mode of communication and deal with machines rather than humans. Traditional teaching and learning was conducted through human-to-human contact before COVID-19, but now it is human to computer to human transmission. As a consequence, a substantial communication gap exists between learners and educators [46]. Online classes are commonly held using platforms such as Zoom, Teams, Tencent Classroom, and Google Meet. However, connectivity problems, massive usage, hardware issues, and the noisy environment of the user affect the quality of communication between learners and educators. People are more comfortable communicating using social platforms instead of educational platforms [35,44]. Non-ICT learners find it hard to keep in touch with their educators and to resume their studies online. They were not accustomed to using computers and were hesitant to follow directions, making it impossible for them to appreciate online education [31].
One of the most critical aspects of education is evaluation. Any educational institution is expected to ensure that assessment proposals are transparent and safe. Due to the pandemic, institutions have moved online to educate learners without a suitable evaluation mechanism [54]. Most institutions are unable to guarantee the appropriateness of the evaluation techniques employed for assessments. There is a significant disparity between offline and online assessments [49]. The Internet possesses many benefits for facilitating online education but presents major obstacles when it comes to assessments, as it is an open platform that can assist learners, and during an assessment, learners can request help from others [47]. Educators are in need of a solution to address the challenge they are facing to assess learners online [54].
When it comes to adopting M-learning for educational reasons, connectivity is a major stumbling block. It is mostly caused by power failures [34]. It may affect the learners, and instructors may have difficulties interacting with them, running courses, obtaining resources, and evaluating learners. This Internet and electricity issue is location dependent. It may vary from 0% in affluent nations and other regions to 90% in third-world countries [42]. According to the World Bank, 84% of European Union member states had access to the Internet in 2018, compared to 66% in Latin America and 18% in the least developed nations (LDC) [55]. Due to their scarcity, measurement and inspection have become exceedingly challenging. M-learning was not widespread in certain regions, and as a result of this pandemic, the education system was compelled to move online. Consequently, there were no established practices or sufficient potential, which contributed to high operational expenses and difficulty in resolving issues [34,41]. Online education requires a high level of data protection and privacy. Confidentiality, integrity, and availability of data may all be classified as technological difficulties encountered while implementing M-learning [32]. When doing laboratory work, Science and Technology students confront considerable obstacles. Providing laboratory facilities in the virtual world is challenging. Medical, engineering, and technology students need a hands-on laboratory environment. This is one of the most pressing problems confronting M-learning. Courses that need hands-on lab work are often hampered by online education because instructors are unable to provide the necessary lab training. As a consequence, learners passed an online course without gaining any hands-on experience [40,49]. Furthermore, the reviewed articles highlight motivational, problem-solving, psychological, and economical issues. The resources required for online education, content preparation, and training are costly and time-consuming [32]. The COVID-19 pandemic struck suddenly, and no one anticipated the ramifications. Moving online to continue teaching and learning occurred unexpectedly. Learners and educators have been forced to confront the issue and adapt to the new norm. Numerous individuals suffer from anxiety and other psychological problems that make it difficult to match with the current practice. The learning environment is different today than it was before since everyone takes courses and exams online. As a result, neither peers nor the institutional environment motivates learners [29,46]. System problems are also listed as a barrier to M-learning.
In addition, learners lack passion and are easily overwhelmed when it comes to formal education through the Internet [56]. Both educators and learners are unable to maintain sustained attention for a prolonged length of time. Concentrating on the lecture is a challenge for learners if the lecture was not interactive and the lecturer lacked the necessary skills to attract learners' attention [32,41]. Figure 4 summarizes all of the identified Mlearning issues.

Summary and Recommendations
To summarize, before COVID-19, most academic institutions were hesitant to employ M-learning for education, resulting in a lack of experience among learners and educators at those institutions in pursuing education online. The pandemic prompted a major shift, leading institutions to leverage online education via M-learning. A huge number of learners and educators went online during this period to proceed with education-related activities. The pressing use of M-learning during this period revealed many insightful experiences, both positive and negative, adding a new perspective toward the use of Mlearning for education for now and the future. Even though face-to-face learning may soon take place for all, there is a high possibility that learners and educators worldwide may continue to leverage M-learning for education. We have analyzed feedback gathered from learners and educators. It is noted that several M-Leaning platforms became popular during the pandemic, and academic institutions were experimenting and leveraging them to pursue with their teaching and learning activities. Many institutions offered their services through these platforms. Although there are other issues such as security and privacy associated with such platforms [57], institutions were compelled to use a third-party platform instead of developing their own due to a lack of time. This review of the pros and cons of leveraging M-learning for education would enable institutions to understand the needs and expectations of learners and educators toward M-learning platforms. It would also aid them in building their own platforms or customizing existing ones to address the shortcomings identified.
The benefits and limitations of using M-learning for Science and Technology courses are discussed above. Here are some suggestions to improve the teaching and learning experience with M-learning. Learners and educators can be given a handbook or demonstration video on operating and using the system. It will be useful to assist both groups in making effective use of M-learning for education. For learners, and even educators, an educational institution may follow different guidelines for different courses. Hence, if the educators use the guidelines, the learning materials will be more resourceful. In class,

Summary and Recommendations
To summarize, before COVID-19, most academic institutions were hesitant to employ M-learning for education, resulting in a lack of experience among learners and educators at those institutions in pursuing education online. The pandemic prompted a major shift, leading institutions to leverage online education via M-learning. A huge number of learners and educators went online during this period to proceed with education-related activities. The pressing use of M-learning during this period revealed many insightful experiences, both positive and negative, adding a new perspective toward the use of M-learning for education for now and the future. Even though face-to-face learning may soon take place for all, there is a high possibility that learners and educators worldwide may continue to leverage M-learning for education. We have analyzed feedback gathered from learners and educators. It is noted that several M-Leaning platforms became popular during the pandemic, and academic institutions were experimenting and leveraging them to pursue with their teaching and learning activities. Many institutions offered their services through these platforms. Although there are other issues such as security and privacy associated with such platforms [57], institutions were compelled to use a third-party platform instead of developing their own due to a lack of time. This review of the pros and cons of leveraging M-learning for education would enable institutions to understand the needs and expectations of learners and educators toward M-learning platforms. It would also aid them in building their own platforms or customizing existing ones to address the shortcomings identified.
The benefits and limitations of using M-learning for Science and Technology courses are discussed above. Here are some suggestions to improve the teaching and learning experience with M-learning. Learners and educators can be given a handbook or demon-stration video on operating and using the system. It will be useful to assist both groups in making effective use of M-learning for education. For learners, and even educators, an educational institution may follow different guidelines for different courses. Hence, if the educators use the guidelines, the learning materials will be more resourceful. In class, quizzes can be arranged to engage learners' attention to the lectures. Learners need to be more focused than in the traditional classroom to achieve this. Furthermore, learners should be encouraged to participate in other group discussions to stay motivated.
Evaluations are necessary for learners, and these must be implemented flawlessly. To prevent cheating, M-learning can include features such as freezing the program so that nothing can be done at that time of assessment and the continuous recording of the participant's video is suggested. Even if the connection is lost, the procedure will remain the same. The answer sheet and the lost session will be instantly uploaded. Finally, the program must be light in weight so that users with low data rates can access it. Implementing any casting can be a useful way to avoid the issue of connectivity.

Conclusions
Education is the backbone of a nation [58]. Therefore, no matter what happens, education should proceed as it was before as much as possible [7]. The COVID-19 pandemic has significantly impacted the education sector. However, learning institutions need to continue devising suitable ways to ensure teaching and learning activities to proceed without much hindrance. It is established from the reviewed articles that education cannot proceed using the traditional way-it needs to change! A new form of delivery is expected, which is possible through the potential of M-learning. The widespread use of mobile learning applications has allowed learners and educators to stay at home and safe during this COVID-19 pandemic; furthermore, this has reduced the spread of the virus through face-to-face classrooms in learning institutions by enabling education to continue online. The challenges and benefits of the current use of M-learning are reviewed following the PRISMA method. This study would aid application developers in improving M-learning platforms for Science and Technology courses, wherein they can identify the present strengths and weaknesses of M-learning implementations and modify them accordingly. Finally, the recommendations included would be helpful to learning institutions in amending their policies to proceed with online education successfully.