Systematic Review of CLIL in Computer Science: Past, Present, and Future — with a Special Focus on Using ICT

. Computer science is regarded one of the subjects best suited for teaching with ICT-supported CLIL, as the English language is the lingua franca of computing, and the computer science classroom is an ideal place to apply digital technologies. This paper aims to explore the role of content and language integrated learning (CLIL) in the teaching and learning of computer science in English – focusing especially on using information and communication technology (ICT). For this purpose, a systematic literature review based on the PRISMA protocol was carried out. A total of 31 documents published in the period 2011–2021 on CLIL in computer science and ICT in the CLIL environment were analysed. In this article, first, the advantages of using CLIL in computer science will be discussed, followed by illustrating the benefits and challenges of applying ICT in CLIL lessons. Finally, trends in research on technology enhanced CLIL will be presented, outlining existing findings as well as identifying research gaps in the field. The most important shortcomings and difficulties outlined in the related literature are the limited research on both CLIL and ICT supported CLIL in the subject of computer science, the inconsistent terminology for using ICT in CLIL, and the need in CLIL teacher training courses for the effective use of digital technologies. Therefore, the findings of this paper identify a variety of future research agendas in order to increase the effective, ICT-supported CLIL in the subject of computer science.


Introduction
Technology has influenced virtually every aspect of life today, and education is no exception. To succeed professionally in the information age, today's students need not only theoretical knowledge, but also other skills and literacies. The vital tools that help to facilitate 21 st Century skills are information and communication technology (Stehle & Peters-Burton, 2019), computer science education (Nouri et al., 2019;Abesadze & Nozadze, 2020), and content and language integrated learning (Vukadin & Markovic, 2019); therefore, teaching computer science in a CLIL environment utilizing a variety of digital technologies might result in a very productive synergy.
From the very beginning of CLIL, the choice of subjects has led to a lot of discussion (Wolff, 2007). While CLIL can be used for a wide range of disciplines, science, geography, history, and social sciences are most commonly taught through target languages (Pérez-Cañado, 2012). Nowadays, it is expedient to teach computer science through CLIL along with other subjects. This subject is known by various names in different European countries and languages (Tikhonenko & Pereira, 2018). "Computer Science," "Informatics," or "Informatics Education," "ICT," and "programming" are the terms used to describe the subject (Diethelm, 2013). Weise (2013) advocates computer science "as one of the subjects best suited for bilingual education." (p. 128). As stated by Marsh (2012), there are more opportunities for learners to learn and master a foreign language than ever before because "ICT, mass-media and Internet usage have expanded dramatically" (p. 245) over the past decades. Alginahi et al. (2009) remark that "Information Technology benefits are best reaped through the knowledge of the English language" (p. 112). Knowledge in the field of IT and computer literacy is mainly acquired through English.
However, there is a lack of knowledge in studies dealing with CLIL in the subject of computer science (Weise, 2013). Weise (2013) wondered why there is "so little tangible interest in bilingual Informatics classes" (p. 129). In his report, Weise (2013) outlined the key reasons why Informatics should be taught in English. To begin with, the language of Informatics is English, and English-language publications are UNIVERSIDAD DE LA SABANA DEPARTMENT OF FOREIGN LANGUAGES AND CULTURES often more accessible than in other languages. Second, high-quality translation of academic content takes time. Therefore, if students want access to up-to-date information in this field, they need to have adequate English language skills. Moreover, students quite often need to understand the technical specifications if they want to learn successfully. In addition, there is a strong relationship between the functions of keywords in a programming language and the meaning of those words in English. It helps to understand the meanings of Informatics terms.
Furthermore, bilingual education prepares students for work in these fields after graduation, as applicants and professionals are required to have specialized foreign language skills, usually in English.
Although the increase in effectiveness through the combination of teaching the Computer Science and English subjects has been pointed out several times, there are not many studies focusing on this topiceither referring to using English or to any other languages.
The present study aims to provide a review of the existing research on the role of CLIL in the subject of computer science, paying special attention to the use of digital tools in CLIL. The following were the research questions that drove and structured the analysis process: RQ1. How is CLIL realized in teaching computer science in English?
RQ2. What is the role of ICT in CLIL classrooms?

Method
This systematic review was guided by the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). The PRISMA protocol developed by Liberati et al. (2009) includes checklist items that should be considered to increase transparency and accuracy of the review process. Items 12-16 and 19-23, which dealt with risk of bias and pooling of results from meta-analyses, were omitted as they pertained to meta-analyses and were not within the scope of this study (Pahlevan-Sharif et al., 2019).
Based on the objectives of the review, a protocol was prepared to guide the literature search. It contains information on search terms, databases, and selection criteria. Four databases were utilized to Data collection was carried out according to the PRISMA protocol, in which the screening process was divided into four established stages ( Figure 1). In the identification phase, a search in four databases using "Cluster 1" returned 3971 records, while "Cluster 2" yielded 1865 records. In the following screening phase, the number of publications was reduced to 27 records in the first cluster and 34 records in the second cluster by removing duplicate citations and applying inclusion and exclusion criteria. Following that, in the eligibility phase, the articles' full texts were examined for the key information outlined in the research questions. Inclusion and exclusion criteria were applied exhaustively at this stage. Finally, at the inclusion stage, 5 articles in "Cluster 1" (RQ1) and 26 articles in "Cluster 2" (RQ2) were collected that made up the study sample.

Results
A total of 31 articles met the objectives of the study and the inclusion and exclusion criteria. An overview of the included articles presented in Table 2.  Note. 1 -a provider of content and instructional tool; 2 -a learning management tool; 3 -a communication and collaboration tool.

Existing findings about CLIL in computer science
In the articles related to the implementation of the CLIL approach in the subject of computer science, each author intended to answer the question of how to effectively teach computer science using CLIL.
For instance, Hrytsiuk (2020) proposes to apply a competence-activity approach and make the learning content more communicative in nature. The author developed a bilingual multimedia course "Computer for Beginners" with a built-in dictionary of English terms, which con- figurative (e.g., a pictogram, an image, a schematic drawing), verbal (e.g., describing a process or situation), symbolic (e.g., object diagrams, graphs), and technical or mathematical (formula-based) form of representation (e.g., source code, pseudo-code, etc.). Based on this model, he presents two pieces of practical, approved teaching material that can be useful for Informatics teachers. Batrova et al. (2017) describes the process of designing the content of the bilingual elective course "Information and communication technologies". The curriculum was developed using the textbooks "Basic English for Computing" (Glendinning & McEwan, 2003) and "Oxford English for Information Technology" (Glendinning & Mc-Ewan, 2002)

Advantages of ICT in CLIL
In comparison to CLIL in computer science, the area of ICT's impact on content and language integrated learning has been extensively studied, and these studies show that the use of ICT in CLIL teaching brings numerous benefits.
The use of digital tools in CLIL classrooms allows teachers to organize various activities that motivate students and develop their linguistic skills (Schietroma, 2019), as well as give them the opportunity to be active participants and developers of their own educational process, instead of being passive recipients of information (Schietroma, 2019). Abaunza et al. (2020) observed in their research that the CLIL approach, together with ICT tools such as Duolingo, provokes the motivation of students who previously showed "a low attitude, low academic performance and a tendency to demotivate the apprehension and acquisition of English as a foreign language" (p. 102).
Hernandez-Nanclares and Jimenez-Munoz (2016) discovered that the use of CLIL in combination with online pre-and post-lecture assignments, social media and blogging as tools for further practice and integrating them into classroom practice improved students' achievement.
They even concluded that, without ICT interventions, the long-term success of bilingual programs and their advantages are severely undermined compared to groups taught exclusively in the mother tongue.
ICTs promote interaction between students and develop basic skills: Trends in research of ICT in CLIL Nunan (2010) defined three major roles of technology in second-language classrooms: technology as a content carrier and instructional tool, as a learning management tool, and as a communication tool.
These roles of ICT can also be applied to the CLIL classroom. The research trends on the application of ICT in CLIL were divided according to these roles.

Technology as a provider of content and instructional tool in CLIL
According to Nunan (2010), the computer acts as a carrier of content when it provides learners with reading and listening input. One of the ways that ICT can be beneficial in the context of CLIL is by adding hypertext and hypermedia, as they allow students to access information about specific concepts or ideas in various forms as written texts, images, videos, simply by clicking on the word they want to study further about. A good example of a CLIL website that uses hy- indicates that videos play a critical role in a CLIL environment as they can be used at different stages of the lesson, such as brainstorming, introduction, practice and assessment, with the aim of engaging and motivating learners in a learner-centered perspective. Zhyrun (2016) discussed the benefits and limitations of developing audio-video materials adapted for university-level CLIL courses, comparing them with existing materials, and concluded that specially created videos were easier to understand and evoke positive emotions as they relate to students' life. Concept maps or mind maps help students to better comprehend the texts they read English (Puspitasari, 2020), encourage them to be more creative, and stimulate cognitive thinking skills.
Probably one of the widely used web-based activities in today's classroom is WebQuests. The effectiveness of a teaching approach where WebQuests, CLIL and STSE (Science, Technology, Society and Environment) were integrated was evaluated by Ángel (2015). The author points out WebQuest as a very attractive method, which provides guidance and structure for both students and teachers and stimulates higher-order thinking skills, describing it as "an inquiry-oriented lesson format in which most or all the information that learners work with comes from the web" (Ángel, 2015, p.1). Fernández-Fontecha (2014) described the CLILQuest as a type of WebQuest for the CLIL framework. The difference of the CLILQuest from the traditional WebQuest is that "the ICT-mediated tasks in a CLILQuest present characteristics that reinforce the dual teaching of content and language by engaging learners in active processing of information and construction of meaningful knowledge" (Fernández-Fontecha, 2014, p. 157 It is worth noting that the authors used the term "e-CLIL" to describe the use of ICT in CLIL classes. In Italy, the Ministry of Education launched a whole project called eCLIL, which pursued the goal of guiding and supporting schools in the preparation and implementation of CLIL modules with the use of ICT technologies. During this project, teachers were trained to apply CLIL and ICT in their lessons, and high-quality resources for students were developed, including project-specific websites, e-books, online assessments, blogs, and more (Cinganotto, 2017).
In her paper, Leto ( The results showed that the CLIL students acquired the same content as the students in the non-CLIL classes; however, their vocabulary was much larger, and they were able to use English to express what they UNIVERSIDAD DE LA SABANA DEPARTMENT OF FOREIGN LANGUAGES AND CULTURES had learned. Moreover, students were more motivated to engage with topics that they had previously found boring. Zaripova et al. (2019) described and assessed how CLIL and ICT improve Master students' motivation. The combination of CLIL and ICT has made it possible to use a constructivist approach, the core elements of which are the ability to explore, experiment, construct, discuss, and analyse.

Technology as a learning management tool in CLIL
Technology as a learning management tool has become increasingly important, especially with the proliferation of non-free software such as Blackboard and Moodle (Nunan, 2010). Albero-Posac (2019)  not have the predominant features of CA-CLIL (flexibility, authenticity, task-oriented, student-cantered, and collaborative); if the role of the teacher is simplified to "lecturer"; if the technology is not used to improve all three phases of mastering a foreign language (input, perception-understanding-reception-integration and output); and if both subject and language goals are not pursued, then the lesson cannot be called a CA-CLIL lesson, and its success can be doubtful.

Technology as a communication and collaboration tool in CLIL
In language while also practicing and broadening their understanding of non-linguistic curricular subjects. Wikis allow teachers to track individual and group progress of students, which can help in determining each student's degree of contribution. In addition, while working on a wiki, students must critically read what others have written, which promotes a higher level of interactivity. The study by Zhao et al. (2021) examined the content knowledge and language outcomes of bilingual students who were exposed to two different learning environmentsa issues from language teachers and researchers, which is understandable given that CLIL is ostensibly a language pedagogy issue, while subject matter teachers' perspectives are uncommon (Veselá, 2012).
Another problem is the inconsistent terminology for using ICT in CLIL: in various literature, the combination of CLIL and ICT is expressed in different terms such as "e-CLIL" (Abbate, 2019;Wojtowicz et al., 2011) or "eCLIL" (Leto, 2017;Cinganotto, 2017) -both referring to the European Union funded project to develop and build digital resources for the use of CLIL -and "CA-CLIL" (Veselá, 2012), that is, computer-assisted CLIL. Moreover, in some literature, this blend is denoted as "TECLIL" (Zhao et al., 2021) or "T-CLIL" (Adipat, 2021) or technology-enhanced CLIL.
Several authors claimed that there is a shortage of sufficient materials dedicated to teaching computer science in CLIL (Griffith, 2017;Wojtowicz et al., 2011). Furthermore, there is a lack of understanding about CLIL methodology and ICT usage among teachers as they use them inappropriately, not taking into account the dual focus of CLIL, using digital technologies without correct methodology -some of them appear to be difficult to use, or they cannot take full advantage of all UNIVERSIDAD DE LA SABANA DEPARTMENT OF FOREIGN LANGUAGES AND CULTURES their features (Griffith, 2017;Navarro-Pablo, 2019;Veselá, 2012). Therefore, there is a need for CLIL teacher training courses where teachers can learn how to use CLIL methodology and digital technologies effectively in their classes, as well as online communication places for exchanging ideas and experiences (Hrytsiuk, 2020;Wojtowicz et al., 2011).

Conclusion
The analysis of thirty-one papers provides an insight into the current state of the use of CLIL in computer science and the application of digital technologies in CLIL classrooms. The findings demonstrate that using technology-enhanced CLIL in computer science can assist learners in becoming more motivated, building language and content skills in the field of ICT, and developing lifelong learning skills. In order to more effectively teach computer science in the CLIL environment, the researchers recommend paying attention to the visualization of the input, using variety forms of presentation of the new material, working with specialized vocabulary, using ICT tools that require interactivity and collaboration and help to develop higher-order thinking, creativity and lifelong learning skills, as well as applying a competence developmental approach. It is also suggested to use a digital course of the subject with various activities that allow students to practice at their own pace and access from any location.
Among the limitations of the study is the fact of the exclusion of articles that are not written in English. It should be recognized that there may be many papers reporting teaching methods in other languages that have likely not been reviewed. Inclusion of only journal articles and conference proceedings is also another limitation, as this may result in the omission of valuable data that may be present in edited editions.
Progress has been made in the research of ICT-supported CLIL, but many important research questions remain -especially regarding the subject of computer science. The above-collected findings of the literature review can be used as recommendations for future research directions and thereby for filling the detected research gaps.