Advantages and Challenges of Teaching Graphic Novels in English Classrooms: A Systematic Review

Graphic novels are a multimodal format that is growing in popularity, and they are increasingly being used as part of the literature curriculum in schools around the world. However, for a variety of reasons, graphic novels continue to be met with scepticism, and many instructors are hesitant to include them into their classrooms. This paper presents a systematic literature review of 18 relevant published research on the teaching of graphic novels in the English classrooms (English as a Second Language [ESL] and English as a Foreign Language [EFL] contexts) around the world for the past decade from the year 2012 to 2022. The findings highlight the advantages and the challenges of the teaching of graphic novels in English classrooms. Results revealed that there are five advantages of teaching the multimodal medium in the English classes which are; improved comprehension, boost reading motivation, enhance critical thinking skills, increased vocabulary acquisition and improved English-speaking proficiency. The review's findings also show that there are three key challenges in teaching graphic novels; lack of visual literacy among students and teachers, lack of instructional strategies and scepticism towards graphic novels. Furthermore, it was also discovered that the visual element of graphic novels which contribute to the primary benefits, is also the one that presents the greatest challenge. The limitations of past studies and recommendations for future research were also discussed.


Introduction
The traditional concept of literacy is rooted from the ability to read and write. For decades, these two skills have been considered as the primary core for a literate person (Walsh, 2017). In addition to the two core skills, according to Australian Curriculum, Assessment and Reporting Authority (ACARA), 2016 (as cited in Walsh, 2017), listening and speaking skills along with the ability to create and to reflect on multimodal texts are also included as the critical skills that fall under the concept of literacy (Walsh, 2017;Brugar et al., 2017). However, over the decades, literacy in education has witnessed major evolvement due to the rapid changes by digital communication technologies. cause students to lose interest in classic written literature entirely. On the other hand, Hansen (2012) mentioned in her paper that graphic novels are subjected to a great deal of criticism, much of which reveals a dislike for new things rather than a thoughtful critique of the genre as a whole. Therefore, the goal of this systematic literature review is to provide an overview of the synthesis of empirical evidence from similar research conducted over the last decade on the benefits and challenges of teaching graphic novels in the English classrooms around the world. Hopefully, as a result of the evidence, teachers' perceptions toward the use of the multimodal medium as teaching materials will improve and for them to be better prepared to face the challenges of teaching graphic novels in the classrooms. Furthermore, other scholars working on the topic may find the synthesis offered in this study valuable in doing additional research in the future. The two main objectives of this study are as follows: 1. To identify the advantages of teaching graphic novels in English classrooms. 2. To identify the challenges of teaching graphic novels in English classrooms.

Literature Review Definition of Graphic Novel
The term "graphic novel'' was first used by Richard Kyle in 1964, however, Kunka (2015) mentioned in their review paper that this reference may not be entirely accurate. Despite this, a few scholars agreed that the term "graphic novel" was widely used and gained its popularity in 1978 when a collection of tales about a crowded, impoverished Jewish neighbourhood in the Bronx called 'A Contract with God' was created by cartoonist Will Eisner (Bucher & Manning, 2004;Smetana et al., 2009;Rajendra, 2015). The term became more popular when eight years later, the graphic novel "Maus" by Art Spiegelman was first published (Hoover, 2012). According to Gorman (2003), (as cited in Chun, 2009), a graphic novel is a book-length work of fiction or nonfiction that is formatted like a comic book. Simmons (2003) (as cited in Bucher & Manning, 2004) provides a more detailed explanation on what graphic novels are-they are a dynamic combination of words and image that conveys meaning and entertainment. A graphic novel has boxed-off text and images, similar to a comic book and the illustrations enrich and extend the text. Adding to the definitions mentioned, Cary 2004 (as cited in Rajendra, 2015) defines graphic novels rather simply; narratives delivered through a sequence of images.
Since both use layout in frames and rely heavily on artwork as their major source of information, graphic novels and comics are inextricably linked to one another. However, there are some major features from graphic novels and comic books that could help educators to differentiate one from the other. A graphic novel differs from a comic book in that it is lengthier and tells a whole story on its own, as opposed to comics, which are frequently published in instalments. This is how Diamond Comics, a significant U.S. distributor, describes the difference as mentioned by Bucher & Manning (2004) in their paper. This is agreed by Clark (2013); Weiner (2002) (as cited in Rajendra, 2015) which mentioned that the narrative of a graphic novel has a start, middle, and end. In addition, several graphic novels have more complicated plots that are meant for mature readers. This is because readers of graphic novels must not only understand the words and the illustrations, but also recognise the events that occur between the visual sequences (Bucher & Manning, 2004;Cleaver, 2008;Smetana et al., 2009).

The Roles of Graphic Novels in English Classrooms
Art Spiegelman's Maus: A Survivor's Tale showed that graphic novels could accurately portray the historical interactions between structural forces and individuals. Graphic novels started to be viewed as a genuine form that could depict the past in a totally different way when Spiegelman won the Pulitzer Prize in 1992 (Clark, 2013). In other words, it was Spiegelman's art that first inspired people to think about including intellectually substantive graphic novels in the curriculum because of the rich and multi-layered narrative style. Subsequently, graphic novels served few significant functions in English classrooms. According to multiple researchers, teachers use graphic novels as a multimodal medium to improve multiliteracies among students. Graphic novels provide the ability to advance a variety of literacies, including progressive, critical, and visual literacies because they are interwoven with words and pictures (Rajendra, 2015). Similarly, Brugar et al (2017) summarised a few prior studies in their research and emphasised that for students to build multimodal literacy skills, they must engage with texts critically and reading graphic novels has the benefit to build those skills. Additionally, The New London Group (1996) (as cited in Brugar et. al., 2017) mentioned that incorporating multimodal literature (such as graphic novels) into the texts used in classrooms will expand the range of opportunities for various groups of students to critically interact with complex concepts and ideas. Furthermore, graphic novels also serve as a useful teaching resource for visual learners. This is particularly crucial given that a growing portion of today's kids are visual due to their early exposure to the fast-paced, visual stimulation of television and video games. Graphic novels encourage students to read and help readers build stronger visual literacy because they connect words and visuals in a unique way. Additionally, students are given the chance to analyse how interconnected words and pictures can construct a compelling sequential story which will help to develop stronger multiliteracies skills (Williams, 2008;Oz & Efecioglu, 2015). On the other hand, Downey (2009) emphasised that graphic novels serve as literary and cognitive models that improve comprehension. According to Oz & Efecioglu (2015), who also said that as the texts and visuals are connected, graphic novels will not only encourage greater comprehension but also aid young learners in learning more effectively. Next, graphic novels are also used as a scaffolding strategy in the classrooms. In a study conducted by Frey & Fisher (2004), it was proven that the use of graphic novels in addition to other genres; Japanese manga and anime as an intervention in the classroom improved students' writing skills as well as their knowledge of ideas and information. The authors emphasised that graphic novels offered a sort of visual language for scaffolding writing strategies where it gives students instruction on the principles and practises of writing. Oz and Efecioglu (2015) also mentioned a similar idea on visual language where students may comprehend unknown vocabulary words as a result of the visual context clues' scaffolding effect from graphic novels. A study conducted by Mauer (2018) aimed to determine whether graphic novels or regular books may help students in one middle school in the United States understand and remember texts reported the same result. The study reported that when participants are given scaffolding in the form of images, they regularly demonstrate improved understanding and can recall texts more precisely. In addition to functioning as educational tools to visual learners and scaffolding strategy, the complex narrative of graphic novels taught in classrooms also depict numerous sociocultural issues that will tremendously benefit students. Oz and Efecioglu (2015) provide an example from a graphic novel written by Henry Yoshitaka Kiyama in 1931 titled 'The Four Immigrants  (2004) and 'Palestine' by (Saco, 2002). These novels depict narratives of great severe injustice, strife and war which will inspire empathy within the readers. Additionally, because empathy is one of the most important topics it raises, this kind of material has the potential to provide students a sense of human connection. Subsequently, Downey (2009) argues in their paper to include graphic novels in the curriculum mainly because, in a clearer way, the multimodal medium presents various ideas and notions about society, history, customs, and life and gives voice to minority viewpoints. The author also added that even though graphic novels frequently reflect the culture and background of their authors, the classic storytelling aspects are still present in these books. They instead are enhanced by the artist's moral compass and point of view. In light of this, it is evident that graphic novels expose students to a variety of peoples and civilizations that they may otherwise miss.

Teachers' Reluctance Towards Teaching Graphic Novels in The Classrooms
Graphic novels undoubtedly serve essential educational purposes as discussed earlier, but it is also undeniable that some educators still have a negative perception of the new literary medium which results in their reluctance to utilise graphic novels in the classrooms. In a 2017 study by Yusof, Lazim, and Salehuddin, it was revealed that even though trainee teachers at the Institute of Teacher Education in Negeri Sembilan had a favourable overall opinion of teaching graphic novels to ESL primary school pupils, there are some respondents indicated that they did not prefer graphic novels. They mentioned that graphic novels could be confusing and unstructured because of the small size visuals that shared the space with the minimal texts. They also added that the importance of in-depth descriptions of the scene, the people, even the tone and emotions, was lost in graphic novels. This exact argument may be the reason why many believe graphic novels are too simple and not suitable to qualify as legitimate literature, as highlighted by Clark (2013); Rajendra (2015) in their studies. However, a lot of graphic novels deal with the same grave topics and issues that are covered in more conventional forms of literature (Bucher & Manning, 2004). Many graphic novels depict the narrative of social justice and humanity that could be chosen accordingly and taught in the classrooms. Additionally, Hansen (2012) noted in their article that images and drawings are not always less valuable than spoken, "literary art," even if the pictures in graphic novels are not thought of as "real literature." In actuality, visuals frequently communicate a complexity and depth of concepts that call for interpretation and advanced critical thinking, analysis, and evaluation skills. Furthermore, referring to the graphic novel's visual components, some educators mentioned that they are hesitant to include graphic novels in the classrooms because the images might be inappropriate in the academic context. According to a 2011 study of pre-service teachers, the top reason why they choose not to utilise or teach graphic novels in the classroom was due to the visuals that depicted brutality or violence towards women where they mentioned that these visuals should be shielded from students (Mathews, 2011). However, according to Hansen (2012), while this criticism might be justified in some cases particularly when young children are the target audience, not all kinds of graphic novels fall within this category. The material of graphic novels can vary greatly; therefore instructors should choose their materials carefully to avoid making claims of this nature. According to Bucher and Manning (2004), educators must be knowledgeable about graphic novels and know how to choose ageappropriate examples for young adults that will appeal to readers and will effectively educate them.
Next, the fear that pupils would completely lose interest in classic written literature is another major reason why educators have been reluctant to teach graphic novels in the classroom. Jaffe and Hurwich (2018) highlighted this particular concern in their book raised by a reader who mentioned that graphic novels may discourage individuals from reading books and instead focus entirely on popular culture. This issue is also raised and discussed by Schwarz (2002) who mentioned that some people are afraid that graphic novels will diminish the important value of written texts, replace quality texts, or discourage the reading of other genres. Jaffe and Hurwich (2018) addressed this issue and emphasised that classic books and graphic novels both offer unique reading experiences, thus there is no reason why they should be mutually exclusive or precluding from one another. As a result, this will expose students to various forms of literacy and improve their multiliteracies skills. Finally, the absence of teaching strategies for graphic novels is the one of the most frequently cited reasons given by educators for choosing not to teach them in the classrooms. A poll on teachers' opinions on graphic novels and their use in the classroom was conducted by Lapp et al. (2012) and the result disclosed that while elementary instructors claimed to be willing to employ graphic novels in the classroom, their actual teaching practices revealed otherwise. Due to a lack of instructional methods and the teachers' degree of familiarity with the medium, their attempts to incorporate graphic novels were largely unsuccessful. Similar to this, a research by Annett (2008) of six English teachers from middle schools, high schools, and colleges revealed that while they were eager to teach English using graphic novels, their lack of knowledge with the medium prevented them from doing so. However, because graphic novels are rapidly being incorporated into the curricula of schools, numerous scholars are creating guidelines on how to teach graphic novels, which will be covered in the next subtopic.

Approaches in Teaching Graphic Novels
Due to the rising popularity of graphic novels together with their importance of incorporating them in the classrooms, scholars around the world are continuing to explore the teaching strategies and approaches on how to teach graphic novels in the classrooms. One other reason is also because as mentioned previously, one of the most common justifications given by educators for choosing not to teach them in the classrooms is the absence or the lack of teaching instructions. In their book, 'Worth a Thousand Words: Using Graphic Novels to Teach Visual and Verbal Literacy ' Jaffe and Hurwich (2018) has divided the two fundamental elements of teaching graphic novels. Making sure that students can analyse and comprehend images critically comes first, followed by teaching them to recognise key terms and elements of graphic novels. The authors mentioned that the first component emphasised on visual literacy. Before incorporating graphic novels in the classrooms, educators should assess students' visual literacy skills to have a general idea on the students' ability in comprehending images. In today's visual media focused culture, the population of visual students is increasing, hence, to assess their existing visual literacy is highly crucial. After that, educators could start educating them on visual literacy to develop and strengthen the skills that they already have. Next, the second component is to provide students with the language and practical knowledge required for reading, analysing, and debating images in general and the format of graphic novels in particular. Jaffe and Hurwich (2018) provide a step-by-step guide on how to introduce students to the anatomy of graphic novels in their guide book. This skill is especially important because the visuals, text panels, and page design, as well as what is included and what is not, are all deliberately chosen to convey meaning in graphic novels. Therefore, it is important for educators to ensure students understand that comprehension when reading graphic novels requires both verbal and visual literacies (Jaffe & Hurwich, 2018). Similarly, McClanahan and Nottingham (2019) addressed the three major components of graphic novels as mentioned by Jaffe and Hurwich (2018)-visual literacy, key graphic novel vocabulary and synthesising images and text-with a dual-coding theory developed by (Sadoski & Paivio, 1994). According to the dual coding theory, the mechanisms of processing visual information and linguistic information in the brain are connected yet have independent and highly diverse neural pathways. In addition, Mayer and Sims (1994) (as cited in McClanahan & Nottingham, 2019), who created an extension of dual coding theory, assert that interconnections between mental images and associated linguistic constructs improve retention and transfer.
On the other hand, in 2017, Lisa Sun conducted a study in an American urban middle school to explore how graphic novel 'Persepolis' by Marjane Satrapi are valued by Language Arts teachers as resources for critical thinking and reading. During the study, the author worked very closely with one of the teachers at the school and elaborated how they introduced and taught the graphic novel to the students. According to Sun (2017), by providing graphic novels and making them freely accessible in the classroom, the teacher gradually introduced her students to graphic novels while fostering a multiliteracies environment. Consequently, students had everyday access to linguistic as well as multimodal, spatial, and visual meanings. These encounters served as the starting point for educational discussions regarding the characteristics of graphic novels, such as the style of the drawings and the themes of the different texts. The students were helped to better understand the concept of graphic novels through these discussions, which were assisted by visual learners. Lastly, Carter (2007) focuses on teaching high-quality graphic novels that focus on important issues relevant to teenagers for the purposes of assisting youngsters in overcoming the difficulties of adolescence or giving them lessons for a successful future. For this reason, he argues that the use of graphic novels in the classroom has the potential to revolutionise both teaching and learning. The first approach recommended by Carter (2007) is to use a crosscurricular approach in which English and history or social studies teachers collaborate to take advantage of titles that make overt political statements or address topics with broad national and international implications. Secondly, he suggested using graphic novels in the English classroom as a supplement to the existing traditional texts. The third approach suggested by Carter (2007) is to employ contact zone theory when learning graphic novels. The contact zone approach is ideal for investigating injustice and conflict because contact zone is defined as a social setting where two or more cultures interact and clash. These situations are typically characterised by highly unequal power dynamics, such as those that resulted from colonialism, slavery, or its aftermaths, which are still being felt in many parts of the world today (Pratt, 1991). The approach challenges both educators and students to engage in a dialogic discussion to share their viewpoints while critically examining significant issues from a variety of societal and personal perspectives. Moreover, the theory also calls for challenging the authority, the status quo, and other power dynamics. In other words, instead of avoiding conflict, it aims to understand it (Carter, 2007).

Methodology
The guide to conducting a standalone systematic literature review proposed by Okoli (2015) was used to write this review paper. There are eight steps proposed by Okoli to conduct a systematic literature review, however, the second step is omitted as it is not relevant to this paper (the step is concerned with reviews in which more than one researcher is involved). The guide starts with determining the purpose of the review by defining the objectives of the study (refer 1.1). The rest of the steps are summarised as follows

Search Terms
In order to perform a comprehensive search for relevant research papers for this study, a few databases such as Google Scholar, Elsevier, Scopus, Routledge, and Springer e-journals were used to look for relevant publications. In addition, several terms were used in the search for relevant articles. such as "graphic novels in the classrooms," "advantages of teaching graphic novels in the classrooms OR benefits of teaching graphic novels in English classrooms", "challenges of teaching graphic novels in the classrooms OR difficulties of teaching graphic novels in the classrooms". Boolean operators and phrase searches are frequently used to narrow the search and to retrieve relevant and more focused study papers.

Inclusion and Exclusion Criteria
The most significant aspect of the systematic literature review is the inclusion and exclusion criteria which determine whether the studies are chosen or rejected. The criteria are also used to determine which papers will be rejected due to poor quality. The following are the criteria used to determine which studies should be included and which should be excluded

Scope of Study
The selected studies must be empirical research papers discussing the teaching of graphic novels in English classrooms around the world. Thus, review or concept papers that discuss the topic of graphic novels are excluded. Next, this systematic review paper specifically discusses the advantages and challenges in teaching graphic novels in the classrooms. Empirical research papers that focus on areas other than that, such as the approach of teaching graphic novels, are therefore excluded for this systematic literature review. This systematic literature review also focuses on the teaching of graphic novels specifically. Studies that explored the teaching of comic books or comic strips are not included in this review paper. Furthermore, this paper only focuses on the teaching of graphic novels in the English as a Second Language (ESL) and English as a Foreign Language (EFL) contexts only. Thus, the teaching of graphic novels in other subjects such as Mathematics and Biology are excluded.

Publication Year
Only papers published between 2012 and 2022 are included in this study. Using the above search terms and inclusion and exclusion criteria, a total of 18 papers from various sources linked to the teaching of graphic novels in English classrooms over the last decade were gathered to be examined.

Extract and Synthesise Data
The data from the selected studies is extracted and synthesised in this step and tabulation is used to complete this phase in this paper. Finally, the findings must be interpreted, which will be covered in detail in the following section.

Findings
After tabulating the data from 18 studies, two systematic literature review tables were created. Eleven previous papers were chosen to answer the first research question. Three of the articles were published in 2015, two articles were from 2016, one article was from 2017, four articles were from 2020 and lastly, there was one article from 2022. Seven publications, on the other hand, were chosen to answer the second research question. Two articles were published in 2012, one article was from 2014, two articles from 2017, one article was from 2020 and lastly, there was one article from 2022. All the articles included were studies from the previous decade (2012)(2013)(2014)(2015)(2016)(2017)(2018)(2019)(2020)(2021)(2022). Tables 1 and 2 summarise all the information gathered during the studies.  • The inability to distinguish iconic meanings in graphic novels is more challenging for students than word comprehension. • Some teachers in the ELA department think that graphic novels are not appropriate. • Some parents are still sceptical towards graphic novels.

Improve Reading Comprehension
Most of the studies concluded that teaching graphic novels to students in English classrooms increase comprehension among students (Oz & Efecioglu 2015;Pishol & Kaur, 2015;Cook, 2016;Bakar et al., 2020;Aldahash & Altalhab 2020;Kennedy & Chinokul, 2020). It was reported that the addition of images to the text in graphic novels is effective in improving students' reading comprehension. Aldahash & Altalhab (2020) used the 'El Deafo' graphic novel in their study and reported that the images helped students feel less anxious, allowing them to read and understand the contents more easily. Furthermore, Kennedy and Chinokul (2020) conducted a study using a graphic novel 'Frankenstein' with the approach of Scaffolded Reading Experience (SRE) among Thai EFL students to assess their ability to interpret both written and visual information. With the SRE method, teachers can encourage, guide, confirm, and ask questions to help students reach their objectives on their own (Kennedy & Chinokul, 2020). Thus, through a grasp of visual interpretation, teaching graphic novels using the SRE approach assisted students to enhance their comprehension of the graphic novel's content and inspired them to read more. On the other hand, a study by Oz & Efecioglu (2015) using graphic novel 'Macbeth' to investigate the role of graphic novels in EFL classrooms among high school students revealed significant results in aiding students to understand important literary components. Students demonstrated a great awareness of the symbolism, setting, and foreshadowing presented in the graphic novel 'Macbeth', according to their post-test results and answers to interviews (Oz & Efecioglu, 2015). Hence, it was proven that graphic novels evidently help students to gain better understanding and improve their knowledge in literature elements.

Boost Reading Motivation and Engagement
From the eleven articles that were analysed, there were five articles that emphasised graphic novels were proven to boost students' motivation to read and increase their reading engagement (Oz & Efecioglu, 2015;Pishol & Kaur, 2015;Bakar et al., 2020;Kennedy & Chinokul, 2020;Aldahash & Altalhab, 2020). Oz & Efecioglu (2015) reported that the visuals specifically became the catalyst for the EFL students involved in their study to participate in the discussion during the literature class. Similarly, a study by Bakar et al. (2020) revealed that ESL students were more motivated to learn literature when they were exposed to graphic novels. On the other hand, Aldahash & Altalhab (2020) highlighted that compared to books that solely contain text, graphic novels help students concentrate and pay attention to detail, which encourages sustained engagement during reading. In short, the illustrations that accompany the texts in the graphic novels are deemed to be attractive to students thus increasing their interest to read the materials which resulted in their active participation in class activities and discussions.

Enhance Critical Thinking Skills
A significant enhancement of critical thinking skills among students is also one of the most cited benefits of implementing graphic novels in education by scholars (Oz & Efecioglu, 2015;Huh & Suh, 2015;Sun, 2017;Lewis & Lewis, 2020;Gultom et al., 2022). In a study conducted by Huh and Suh (2015), they aim to demonstrate how Korean English elementary students acquire a critical perspective for interpreting graphic novels. In their study, they implemented a few graphic novels like 'The Adventures Tintin' and 'The Geronimo Stilton' and the result revealed that the students were able to challenge the prevalent ideologies of many social challenges in addition to proposing an alternative world outlook that was more oriented toward social welfare equality. Students responded to the texts, for example, by addressing unfairness of prevalent discrimination and racism, gender stereotypes, and certain social conventions connected to academic and school standards. Similarly, Sun (2017) explored how middle school students develop their critical thinking skills by reading 'Persepolis' graphic novel by (Satrapi, 2003). By working very closely with the teacher at the school, the result of their study reported a few valuable findings on students' critical thinking skills. The two prominent findings revealed during the study are students were able to empathise with the character because of how the graphic novel portrays the character from several points of view and places them within a larger context (Sun, 2017). Next, the young readers were also exposed to and assisted in understanding the complicated topics by the complex socio-political events depicted by the graphic novel such as the Iraq War.

Increase Vocabulary Acquisition
Next, there were three studies conducted by the researchers that proved incorporating graphic novels in the classrooms significantly increased students' vocabulary acquisition (Basal et al., 2016;Pishol & Kaur, 2015;Bakar et al., 2020). A study conducted by Basal et al (2015) focused on the teaching of idioms using graphic novels that the researchers created specifically for the study among university students in Turkey. Their findings reported that students who learned English figurative idioms with the graphic novel outperformed the students who learned the same idioms without the use of the graphic novel. This is a result of the multimodalities of the graphic novel where both visuals and verbal information are present in one medium resulting in students' excellent performance (Basal et al., 2015). This means that using graphic novels in English classrooms proves that educators could utilise students' potential to the fullest in the learning process when they process both visual and verbal information to make meanings, which ultimately results in longer information retention.

Improve English Speaking Proficiency
There is only one study that aimed to identify the effectiveness of incorporating graphic novels in improving the fluency of spoken English among EFL learners (Gultom et al., 2022).
The study that was conducted in Indonesia among first year EFL university students, is based on online class observation and a survey that was done on the students after the speaking course, which was taught using graphic novels, ended. The researchers however, did not mention the specific title of the graphic novels used in the study. Nevertheless, the overall result highlighted by the researchers was, most students reported that the illustrations in graphic novels increase their confidence to speak English more in the class (Gultom et al., 2022). Graphics or images as an added element in the graphic novels alongside texts, once again become the main reason students were able to improve their imaginations and encourage them to provide critical perspectives during verbal discussions in the class.

Lack of Visual Literacy
Following the articles' analysis, lack of visual literacy among students and teachers was discovered to be the most frequently mentioned challenge of teaching graphic novels in English classes (Masood & Iranmanesh, 2012;Cimermanova, 2014;Yusof et al., 2017;Yusof et al., 2020). According to Felten (2008), visual literacy is described as the ability to identify, comprehend, and make use of the distinctive syntax and semantics of various visual forms. Being a larger part of multimodal literacy, visual literacy has extended the classic concept of literacy due to the transformation of our environment to be increasingly visual. Thus, the multimodality of graphic novels requires readers to be both visually and verbally literate where a deficiency in either ability will lead to comprehension issues.
Masood & Iranmanesh (2012) conducted a study to compare reading comprehension between visual and verbal learners by employing graphic novel 'Kokko and Toothache', which is easier to read and graphic novel 'Secret of Sphinx', which is more difficult to read. The findings indicated that even though visual learners performed well in their comprehension tests for both types of novels, verbal learners found it challenging and difficult to make meaning from the connection between visuals and texts when they were reading the graphic novels during the study. It was discovered that verbal learners were unable to process textual and pictorial signals simultaneously to derive a single meaning because they are accustomed to relying heavily on words and descriptions when reading (Masood & Iranmanesh, 2012). Similar findings were discovered from a study conducted by Cimermanova (2014) in Slovakia which investigated EFL trainee teachers' ability to read and analyse graphic novels. It was discovered that the trainee teachers were heavily reliant on texts and found it challenging to comprehend the intricacy of graphic novels. The researcher highlighted one of the participants' perceptions which emphasised on how it was difficult for them to describe or explain the graphic novels using words. The participants had to be more imaginative in their descriptions of what they had read because graphic novels include a lot more visuals than words, thus they could not copy or reuse the words as frequently as they always did. (Cimermanova, 2014). Thus, it was discovered that adult learners, in this context, the teacher trainees also lack visual literacy because they are too used to being heavily dependent on words.
On the other hand, a study from Yusof et al (2017), found that students were more preoccupied with the images and have failed to read the words in speech balloons while reading the graphic novels in class due to a lack of visual literacy and multiliteracies. This eventually caused them to comprehend the content incorrectly and their input became unclear. Hence, the study's findings emphasised the necessity for formal instruction in visual literacy, according to the researchers. It is also necessary to teach students to understand how to create and analyse visual information as well as how to be aware of the lexicon of forms and colours. Additionally, students should develop skills for selecting which information to concentrate on as well as learn how to read in both verbal and visual formats (Steeves, 2015 as cited in Yusof et al., 2017) to ensure students could gain better understanding of the content in addition to developing their multiliteracies skills. Next, a study conducted by Yusof et. al (2020) specifically observed how students read graphic novels through eye movement analysis. The anatomy of graphic novels consists of the combination of textual and visual features as well as the arrangement of the features in sequential units. Thus, the components that bring all the elements together to create the medium, such as panels, gutters, speech balloons and narrative box, are regarded as truly unique (Yusof et. al., 2020). As a result, reading graphic novels differs significantly from reading traditional text novels in terms of both chronology and approach. The findings from the study revealed that when the layout of the graphic novel uses the two varieties of the page layout known as "blockage" and "staggering," students have trouble accurately navigating the sequence of panels when reading. According to the authors, other similar studies also mentioned that the two layout varieties are particularly difficult for beginners who read graphic novels. Therefore, it is not surprising that the study's participants, who were unfamiliar with graphic novels, also find it confusing when they read panels that have a blocky or staggering pattern (Yusof et al., 2020). This shows that, even though comic books, which students may be more familiar with, and graphic novels share a similar layout, teachers should teach their students about graphic novels' features and components and how to read them correctly so that they may better understand the valuable content that the multimodal medium offers.

Lack of Instructional Strategies, Awareness and Resources
From previous discussion, it was discovered that both students and teachers have difficulties in comprehending the content of graphic novels due to lack of visual literacy. After analysing all the shortlisted articles, it was found that the biggest contributor to this problem could be because of the lack of instructional strategies provided to teachers to teach graphic novels to the students (Lapp et. al., 2012;Yusof et al., 2017;Sinha & Malshe, 2017). One of the findings from Yusof et al (2017), which explored the difficulties trainee teachers encountered when teaching graphic novels to students in primary schools, found that most of the trainee teachers stated they did not explain the elements of graphic novels to their students before they began teaching. They claimed that in addition to being unaware of the significance of teaching graphic novel components to their pupils, they also believed that doing so was superfluous given that the major goal of the lesson was to comprehend the story's content. The researchers also found that not all trainee teachers were specifically trained to teach graphic novels because the genre was only included in the Language Arts syllabus in 2011. Furthermore, some of the trainee teachers also acknowledged that because they lacked pedagogical skills on how to use the genre successfully, they continued to employ the same ineffective teaching techniques that eventually bore their pupils. Therefore, this became the reason that the teachers were unable to successfully teach graphic novels to the students.  (2020) found that even though the teachers are supportive in incorporating graphic novels in their classrooms, they are still reluctant to adopt the multimodal medium due to lack of training and instructional models provided to them. In addition to that, teachers also mentioned that they do not have enough time allocated to introduce the genre to the students due to the tremendous pressure to finish the syllabus by the specified time given to them (Sinha & Malshe, 2017), not knowing that graphic novels are commercially available and low degree of comfort utilising graphic novels in the classroom (Sinha & Malshe, 2017;Lapp et. al., 2012).

Scepticism Towards Graphic Novels as Learning Literature Resources
After analysis, there is just one article that reveals some teachers have concerns about the reliability of using graphic novels as a teaching tool in the classroom. Higginbotham et al (2022) sought to explore how English Language Arts (ELA) teachers thought graphic novels affected their students in the classroom and found that four out of fourteen of the teachers explicitly acknowledged that they did not consider graphic novels to be proper literature but rather abbreviated versions of stories that will not benefit students in the classroom. In addition, the teachers emphasised that they had been questioned by some worried parents about whether graphic novels are the correct content to expose the students to, particularly if their children are having difficulty reading. The authors went on to say that this is a result of the fact that parents and educators believe graphic novels are not rigorous enough for students and that the genre is only appropriate for leisure reading rather than academic study (Higginbotham et al., 2022). Hence, it is not feasible that the advantages that graphic novels offer fail to reach the students and cannot be utilised to their greatest potential if educators and parents lack sufficient confidence in the material that they are teaching.

Discussion
This systematic review on the teaching of graphic novels in English classrooms reveals two major findings that answer the research questions. Firstly, it was discovered that there are five advantages of teaching the multimodal medium in the English classes which are; improved comprehension, boost reading motivation and engagement, enhance critical thinking skills, increased vocabulary acquisition and improved English-speaking proficiency. Secondly, it was found that there are three main challenges of teaching graphic novels that emerged from the review; lack of visual literacy among students and teachers, lack of instructional strategies, awareness and resources of graphic novels and scepticism towards graphic novels as learning literature tools. From the analysis, it appeared that the visual element of the graphic novels which contribute to the primary benefits, which is improved reading comprehension, is also the one that presents the greatest challenge which is, lack of visual literacy. For easy reference, this particular finding is tabulated as below

Advantage
Improved comprehension due to additional visuals element

Challenge
Unable to make meaning from the visuals due to lack of visual literacy Based on the table 5 above, majority of the empirical studies reported that the interweaving of the elements of visuals and texts help students gain better understanding and interpret the content more accurately (Oz & Efecioglu 2015;Pishol & Kaur, 2015;Cook, 2016;Yusof et al., 2020;Aldahash & Altalhab 2020;Kennedy & Chinokul, 2020). However, the visual elements are also causing the main difficulty for both students and teachers to comprehend graphic novels as a whole due to lack of visual literacy (Masood & Iranmanesh, 2012;Cimermanova, 2014;Yusof et al., 2017;Yusof et al., 2020). In today's visually oriented culture, although the vast majority of people worldwide are already accustomed to understanding information presented mostly through pictures, the findings from the studies clearly suggest that visual literacy is crucially needed to be taught formally in the education settings (Felten, 2008;Yusof et al., 2017;Jaffe & Hurwich, 2018). This eventually could solve two major issues in teaching graphic novels which are; lack of visual literacy and instructional strategies. As a result, when both students and teachers have the skills needed, an effective learning process can be achieved. Next, despite the fact that graphic novels continue to face criticism due to its unique components of visuals and texts which become the reason it was not accepted as a true literature, from this systematic review, it was discovered that there is only one empirical finding that reveals some concerns from parents and teachers towards the genre (Higginbotham et al., 2022). This may be attributed to growing discussions and research by academics worldwide that demonstrates how graphic novels are a resource that may offer and serve students and educators complex social issues, as demonstrated by a few of the studies presented in this systematic review. Some of the graphic novels that are employed in the studies like Macbeth by William Shakespeare (Oz & Efecioglu, 2015), and Persepolis by Satrapi (Sun, 2017;Lewis & Lewis, 2020) have been proven to enhance critical thinking skills among the students. The graphic novels' intricate narratives, which represent multiple sociocultural issues, entice students to challenge dominant ideologies and allow the readers to empathise with the characters presented in the graphic novel.

Limitations and Recommendations
This systematic review has evidently presented the advantages and the challenges of teaching graphic novels in English classrooms which will benefit educators who wish to incorporate the multimodal media in their classes. However, it is acknowledged that there are two limitations present while conducting this systematic review. Firstly, it was quite time consuming to locate empirical studies that have a specific focus on graphic novels. This could be for two reasons; firstly, as mentioned by many scholars, the empirical studies on incorporating graphic novels in the curriculum is still scant. There are however quite many papers that generally discuss the topic of graphic novels without any empirical evidence. Secondly, it could be because the definition of graphic novel is still quite unclear as it is always associated with comic books or comic strips. This brings to the second limitation where some studies use the term 'graphic novels' and 'comics' or 'comic strips/books' interchangeably. Thus, confusion and misunderstanding might occur especially to some people who still think graphic novels are not real literature. Thus, for more reliable evidence and findings this review paper solely examines graphic novels. In addition to that, the differences between graphic novels and comics are readily explained in subtopic 2.1 to provide a clear distinction between the two genres. Moving forward, it is highly recommended for future research to explore the approaches and methodologies of teaching graphic novels in classes to examine the effective methods in order to offer options for educators around the world on how to teach graphic novels as part of the curriculum. Many educators continue to argue that the absence of effective teaching methods is the main reason they are still hesitant to integrate graphic novels into the curriculum (Lapp et. al, 2012;Yusof et al., 2017;Sinha & Malshe, 2017;Aldahash & Altahab). Thus, if there is a systematic review paper which solely examines the approaches of teaching graphic novels in the classrooms, it could be used as a guide that educators can refer to and allow them to analyse which approach or strategy is most effective in their context.

Conclusion
In conclusion, this systematic review has highlighted the advantages and challenges of the teaching of graphic novels in English classrooms around the world. The notion of utilising sequential art narratives as teaching materials in the classroom, which is quite unconventional, has made graphic novels continue to face various criticism. However, the findings of this systematic review have revealed that the multimodality of graphic novels evidently can serve tremendous benefits to ESL and EFL students. Undeniably, the teaching of graphic novels also comes with its issues and challenges, although, they do not preclude the opportunity of incorporating graphic novels in the curriculum completely. The issues and challenges are believed could be overcome with cooperative efforts from the educators. Therefore, the results from this systematic review are hoped to be beneficial to ideally shift teachers' attitudes of the use of the graphic novels as teaching materials and help them be better equipped to overcome the difficulties of implementing graphic novels in the classroom.