Local-Based Content to Improve EFL Students' English Achievement: A Systematic Review

The study carries out a systematic literature review to collect evidence and drew a holistic picture of the effectiveness of local-based content in the EFL materials on learners’ reading, listening, writing, and speaking skills. The systematic review covered several databases including EBSCO and Google Scholar as well as leading publishers such as Emerald. The study adopts systematic search, analysis, and synthesis of published studies and research results relevant to the local-based content functioning in EFL materials were extracted. Specifically, the review extracted 49 peer-reviewed articles published between 2012 and 2020. The careful analysis of these articles revealed a medium to large effect of local-based content on reading and listening skills. However, there is unclear evidence of its effect on writing and speaking skills.


Introduction
Theoretical consideration and global practical experiences establish the English language as an international language that non-native speakers utilized more commonly in multilingual communications than native speakers do (Vodopija-Krstanovic & Marinac, 2019;McKay, 2018). Due to this fact, learning English manifest a substantial need to communicate globally and progress professionally. Accordingly, English is educated in schools and universities and for young adults as a foreign language (EFL) or second language (Mahmud, 2014). Further, it extends to become the medium of educating and instructing in various settings. Despite that, EFL learners, particularly those who are in the earliest stages of language learning, find and face difficulties to understand spoken language and comprehending written texts (Hussein & Albakri, 2019;Namaziandost et al., 2019;Kara et al., 2017). Mentioning the most common challenges and difficulties is categorized as a factor of text as an external factor juxtaposed to learners' background knowledge as an internal factor (Namaziandost et al., 2019).
The vast surge of literature stressed the effect of curriculum contents (topic) on EFL learners' achievements (Jovari, 2020;Namaziandost et al., 2020;Kim & Kang, 2017); since achievement involves interaction between text and prior knowledge of the learner as supported by the constructivism theory. Piaget (as cited in Agustina et al., 2018) developed the constructivism theory, which established that learners comprehend and acquire information from text based on the mental and intellectual reciprocal processing between text and their background knowledge (Namaziandost et al., 2020;Zashchitina & Moysyak, 2017). Furthermore, there is an argument that information can be easily stored and retrieved if the information is related to previous knowledge, such as learners' background (Jovari, 2020;Kim & Kang, 2017). Agreed with Ratminingsih et al. (2020) mentioned that general or sufficient knowledge-related content is associated with EFL mastering skills coinciding with the cognitive norm of language learning. In sum, both social and local factors affect English language learning regularly (Hussein & Albakri, 2019;Kara et al., 2017).
With this in mind, local-based content is assumed to influence EFL learning and achievements since the learners have an enriched prior knowledge of the local content. Consensus with the last running perspectives of 'global thinking, local teaching' in language pedagogy, which sought the effect of familiarity and meaningfulness of foreign language corpus on language acquisition and learners' capacities (Fu, 2018;Kanoksilapatham & Suranakkharin, 2018). Succinctly, adopting local-based content for English foreign language learners can be pivotal for acquiring the English language. Thus, the present study seeks to achieve the following objectives: ▪ To construct a holistic review of operationalization and activating of local-based content to contextualize English language controversies. ▪ To derive an understanding of local-based content that fosters achievements of EFL learners. ▪ To unravel the consensus and controversies on teaching English as a foreign language based on local content.
Local-based contents are an interesting recent development of EFL textbooks and an approach to designing interactive content for EFL. In context, this study will reveal a crucial aspect of how EFL contents can be contextualized and induce new ideas for EFL textbooks' contents, which will have significant pedagogical implications for functioning felicitous content-related local contents for EFL learners to promote their English language acquisition.

Background: Local-Based Contents
EFL learning contents are substantial and influential elements and factors of language acquisition. Hence, some authors describe EFL materials as a "crucial feature" of learning or tutoring language effectively (Rizaldy, 2018). The foremost aspect related to EFL learning materials is that society cannot be severed from EFL contents, which imputed to the myth of language and society as a two-sided coin. In supporting the myth, society and language are inseparable and shared a reciprocal association; since language is both a way to utterance society and a transforming tool for society (Erlina et al., 2018). In other words, the only way to express and communicate within society is by language.
Local-based content is about developing authentic language material that involves local topics and subjects accords the material will be contextual and conversant to learners' society in the hope to enhance their comprehension and support their retrieving abilities (Kusuma, 2016). Furthermore, the familiar content term is a synonym of local-based content. It is defined as a text that involves various facets of the unique learners' society, such as the lifestyle including dressing, food, artefacts, and so forth . However, we do not inherit a specific society definition within the study because, across literature and researchers, there are no consensuses to one unified interpretation, but it will be considered across the review.
There is a controversy of perspectives on using local-based content in teaching English as a foreign language and using local-based content in EFL is still doubtful and researchable. The first perception advances the significance of using "target language contents in the EFL context (Risager, 2018;Hidayati & Tarjana, 2017). The second perspective recommends teaching English in a "local-free" context. The third perception advocates teaching "local contents" in the EFL context rather than the "target language content" proposed by the first perception (Yassi, 2017). Meanwhile, the last perception suggests an equilibrium text based on both target and local contents language (Erlina, et al., 2018;Syahri & Susanti, 2016). The study is in line with the third perception of using local-based content in the EFL context because of the recent prevalence of learning English for recruiting purposes rather than living, studying, or recruiting abroad. Further, EFL learners are not interested in the target language contents (i.e. Western society) and differences between vast western societies. These local familiar contexts make students worthlessly struggle with language acquisition and comprehension for nothing.
Meanwhile, local-based contents yield learners to engage effectively with learning, be motivated to learn continuously, comprehend texts sufficiently, and reflect their society proudly. It is worth mentioning that EFL learners are also motivated to communicate their ideas to others, and if they acquire a language, they will smoothly and conveniently procure the target content aspect of the language. Local-based context integration in the EFL materials may provide numerous pedagogical benefits and strengthen learners. Thus, the current study investigated what previous empirical evidence reported the benefit of localbased materials for enhancing learning English as a foreign language.

Method
The study aims to create a holistic review of functioning local-based contents in teaching English as a foreign language and demonstrates considerably evidence-based practices to reveal the benefits and advantages of such design on learner achievements. Thus, the study adopts a systematic review approach, which implies systematic searching, analysis, and synthesizing continuum of published studies and research results relevant to the localbased contents functioning in EFL materials. Both inclusion and exclusion protocols implemented through search and investigation are illustrated next. The process of a systematic review is based on numerous regular procedures, namely securing transparent steps through searching and reviewing process based on consented definitions, search terms, comprises effort to reduce searching bias to minimum standards, and collecting and synthesizing clear gist of evidence examined in a reliability and validity context.

Review Protocol
The researcher targets different electronic databases, including the EBSCO database, ERIC (Education Resources Information Center), Emerald, and Google Scholar (see Table 1). Inclusion criteria are based on several standards. First, the researcher includes studies that have included one term of each key phrase of research as listed below (see Table 1). Second, the studies published between 2012 and 2021 are counted. Third, peer-reviewed or conference proceeding articles were included. Fourth: the study's methods are either case study, qualitative or quantitative analytical descriptive, longitude studies, or experimental results. Fifth: there is no constraint regarding the gender, age, or education level of participants. Sixth: Only articles published in the English language were included. Seventh: only full text and open access articles were included.
Exclusion criteria are Any studies published before 2012. Any study that has one research term only, two, or three phrases. Any article, which is a systematic review article, meta-analysis, or book chapter was excluded. Any dissertation, master thesis, reports, and unpublished research were discarded. Any studies that did not provide empirical evidence were taken-off. Studies arguing teaching society-based instruction, content-based language teaching, or teaching local content practices were removed, too. Studies-based materials contents analysis or studies-based materials design and development purposes were also taken off. Research on society awareness was also excluded. Studies of English as a second language, English for academic purposes (EAP), and English for specific purposes (ESP) were excluded, too.
It is worth mentioning that all doctoral and master dissertations were excluded from selecting studies since the review only adheres to peer-reviewed studies. However, the findings of an academic dissertation may not demonstrate reliability and validity codes of research, such as in peer-reviewed journals and scholarly journals. Two phases were adopted to refine the selection outcomes. Tire 1: the selection and segregation criteria apply to studies or research titles only. Tier 2: the researcher examines the abstract and keywords of all articles selected in tier 1. Accordingly, the researcher guarantees the reliability of the inclusion approach. Furthermore, to increase results reliabilities, the researcher applies different searching techniques, such as using the thesaurus and advanced research available tools.
The research shared the inclusion and exclusion criteria with the alternative researcher to validate extraction process reliability. Both researchers extracted and inserted evoked studies in different excel sheets. Finally, the agreement degree between the results of the two researchers was 95% that corresponding to a high approved agreement level. Both researchers were settling the difference and discrepancies across studies and research, yielding 57 articles. However, it is surprisingly found multiple identical articles with different titles for the same authors were published in different journals; since the results and contents are identical either the title is varied, thus, only one identical was considered. Furthermore, the review extracted two articles with different titles and authors, but have identical contents and results, both of them were considered due to variations in authors and publication years. Accordingly, the total number of articles was 49 articles.

Description Data of Reviewed Articles
An overview of the articles over the electronic databases is described as shown in Table  2. The Emerald database is poorly represented relevant articles compared to both google scholar and the EBSCO database. However, even ERIC database is not represented in Table 2, it is more indexing frequent than Emerald since all articles extracted from the ERIC database are also indexed by Google Scholar as explaining the multiple database representation occurrences (6.1%). Further, the researchers' interests are approximately constant over the nine covered publishing years, which indicates the novelty and significance of the subjects, existing research gaps, and evidence lacking that advocates researchers to investigate further in the matter.

General Background and Characteristics of Articles
There is a necessity to describe article characteristics to grasp the effectiveness of using local content fostering English language acquisitions, particularly, studies design, targeted sample, materials used, script types (topics), and measurements adopted. Review results of the targeted articles illustrated by dependent variable scopes (i.e. achievement measurement), as succeeding. The current study considers language learning achievement as an advancement or acquisition of any language learning relevant skills such as reading; writing, speaking, and listing, or as achievement in any combination of several skills. Further, the psychological aspect of learning a language is also considered an achievement such as anxiety, self-efficacy, attitudes, and perceptions.  Tables 3 and 4 show articles that assessed reading skills. Table 3 summarizes studies  based experimental approach, while Table 4 presents studies with descriptive nature. The majority of articles concern reading skills rather than other language learning skills (n = 26; 35%). That is not surprising since reading is a receptive skill that students can engage in rather than listening, which is progressing without learner engagement, which is not right in reading. Furthermore, the first sense of material or content in the mind is always relevant to something written rather than something heard or seen. As noticed some studies assessed reading skills as well as learners' engagements such as (Nafissi et al., 2020;. Local-based materials have a significant enhancing influence on reading skills. A majority of studies evaluated reading comprehension as the mature indicator of reading skills. Descriptive studies (e.g., Bensalah & Gueroudj, 2020;Nafissi et al., 2020;Khataee, 2018;Boadhar et al., 2015;Shirzadi, 2015;Sadeghi, 2014;Vahdany et al., 2014;Yousef et al., 2014;Rokni & Hajilari, 2013;Barati & Youhanaee, 2012;Boadhar, 2012;Li & Lai, 2012) established that the students who were taught using local materials exhibited enhancement in the reading comprehension and differences between the baseline and post comprehension levels. The effect size of using local-based materials ranged from medium to large effect according to Cohen's d (0.72 ≤ d ≤ 3.89) (Alali et al., 2020;Ratminingsih et al., 2020). Similar to Etasquared values driven by 2019a; vary from 0.07 to 0.33, noting medium to large effect size (see Table 3). However, some studies further carried out the effect size of using local contents on different reading comprehension levels, such as literal, inference, and elaborative comprehensions. The effect size of localbased material on inference comprehension was medium to large (η2 = 0.07) (Tavakoli et al., 2012); d = 2.20; (Alali et al., 2020). Chen & Lai (2014) found that inferencing local is easier than inferencing unfamiliar content. Likewise, the effect on literal comprehension was medium effect η2 = 0.08 (Tavakoli et al., 2012) and large effect d = 1.42 (Alali et al., 2020). Alali et al (2020) further measured the effect size on evaluative comprehension and found a considerable effect of local-based contents on evaluative comprehension d = 2.27. Students discoursed that curiosity to read local contents is higher compared to other counterpart contents. The experimental group has a higher mean score on the free recall test since the experimental group was exposed to familiar stories Difference is significant (Sadeghi, 2014 They further asserted that local contents facilitate reading comprehension. Both selfreports of students and teachers opined there is an association between local-based content and reading comprehension (Liu, 2015;Nachmani, 2015;Khanam et al., 2014).

Reading Skills
In the contrast, Karim and Nafissi (2017) found martial orientation design did not have any significant effect on reading comprehension. This is imputed to the lack of comprehension test design in the study because the comprehension test cannot exhibit differences between students due to the lower number of questions and question type. As shown by Barati and Youhanaee (2012), question type affects the obtained scores in reading comprehension. 2019a) measured the reading skills based on vocabulary retention or recall. The effect size on vocabulary retention η2 ranged from 6% to 21%, which supports the results of Boadhar et al (2015); Darvand and Ketabi (2015); Davoudi and Ramezani (2014) that there is a difference between vocabulary retention scores between local (familiar) and target or global contents. Darvand and Ketabi (2015) found that lexical retention and inferencing are easier in familiar (local) contexts rather than in counterpart contexts.
The majority of studies ensured equivalent language proficiency among participants at the baseline phase. Meanwhile, the level of language proficiency interprets reading comprehension outcomes since the effect size of proficiency is large (η2 = 0.502; . Further, Nafissi et al., (2020) found the material orientation design cannot override the high proficiency level of reading. Gurkan (2012) found the effect of local-based material can be enlarged if it is combined with pre-reading activities of activating prior knowledge. Li and Lai (2012) found that localbased materials affect reading speed similar to comprehension. The experimental study was replicated or extended at the educational levels, supporting that the local-based contents' effect is independent of the educational level.

Listening Skills
Only 12% of the articles concerned listening skills. This percentage is not adequate with respect to the percentage of those addressed reading skills. However, Namaziandost et al. (2018) estimated the effect size of using local-based contents was large (local content: η 2 =0.915). Similar to Samian and Dastjerdi's (2012) results, carried a large effect size of local contents compared to British and American and free locally contents (d = 1.33; 3.24, respectively), and a medium effect compared to international content. Carson (2019) explained the effectiveness based on students' reports, since they did not report perceived difficulty in local-based materials and registered higher vocabulary gains compared to counterpart contents.
All studies asserted the effectiveness of using local-based materials to enhance listening skills (for example, Mahmoudi, 2018, Tous & Haghighi, 2013. Contradictory to results in reading comprehension studies, gender has an affecting role on listening comprehension in favour of male learners (Namaziandost, Sabzevari, & Hashemifardnia, 2018). The material orientation design cannot override the higher level of listening comprehension and reading comprehension (Pashayi & Mahmoudi, 2017).

Writing Skills
As noticed, speaking has not been of interest or attention to any concerns of authors seeking the benefits and advantages of developing EFL materials based on local-based content.  (Nachmani, 2015) Yes (45)

Oral Representation Skills
Only three articles considered the sealing skills of language learning. Accordingly, speaking has been given less care and interest in the context of local-based materials in EFL learning, research, teaching, and assessment. Nevertheless, the local-based materials have a significant positive effect on oral and verbal skills (Qiu & Lo, 2016;Kazemi & Zarei, 2015;Shabani, 2013). These three studies used distinguished assessment indicators, for example, word count, time, production, and relevant clauses. Only Kazemi and Zarei (2015) used a standardized checklist of oral presentation assessments. Furthermore, the three studies targeted different age levels. Hence, the comparison between levels is not plausible. All studies used a one-group experimental design.

Learns Psychological Background
Psychological characteristics may affect the role of local-based content on learners' acquisition of language. Thus, there is considerable interest in this issue while studying the effectiveness of the local content on EFL learning. Approximately, a third of studies (n=19; 38.7%) considered a psychological aspect of learners (see Table 7).
Most studies share a consensus that local-based content increased the learner's motivation (Lasekan & Godoy, 2020;Zhang et al., 2018;Karim & Nafissi, 2017;Segni & Davidson, 2016). Thus, learner engagement increased correspondingly to using local content (Sheridan, Tanaka, & Hogg, 2019;Segni & Davidson, 2016;Qiu & Lo, 2016;Ebe, 2015). Which is in line with results obtained by Zhang et al., 2018 andAubrey (2017), who found that learning local content is associated with higher attention, confidence, and relevant feelings. Keep this in mind, several studies reported a positive and strong attitude toward using local content since they reported easier and faster learning in the local-based context (Lasekan & Godoy, 2020;Selvarasu, et al., 2020;Mahardika, 2018;Li & Lai, 2012). Even the positive attitudes toward using local-based content, there is a negative attitude and strongly rejecting nativization process of international content to local content and there is a preference to read the text in their original version rather than anticipated. Also, teachers were against the nativization process, they claimed that the nativization process leads to language elements exclusion from society (Forman, 2014).
Teachers exhibit a positive attitude toward local content integration because they can know more about their emergent bilingual students. The activities of finding and reading relevant text reveal various information about students' preferences, skills, attitudes, orientation, and so forth (Ebe, 2015). Accommodating teachers' feelings of being unsettled and excluded when teaching international or spoken source language texts. Not mentioning, the resistance and less engagement from learners against what they may feel with local-based content (Forman, 2014).
In terms of anxiety, Nafissi et al (2020); Karim and Nafissi (2017); Segni and Davidson (2016) agreed that familiar, quite familiar, and partially familiar contents provoke lower reading anxiety levels compared with anxiety levels that were stimulated by unfamiliar contents for most students.
In terms of self-efficacy, only Nafissi et al (2020); Karim and Nafissi (2017) determined the differences in reading comprehension self-efficacy among different material-oriented designs and pinpointed that there is an alleviation gain of self-efficacy among students in the different oriented design of material without any real differences among them. Accordingly, the study repudiated the effect associated with material design on self-efficacy levels.

Learner Achievement
Only three articles used the Achievement phrase to measure learners' acquisition of language (see table 8). Achievement may include more than two skills of language learning. For example, (Lasekan & Godoy, 2020) measured multiple language skills of reading, speaking, listening, and writing. Meanwhile, Zhang et al (2018) assessed only writing, reading, and speaking skills.  did not precisely define achievement meaning and only assessed vocabulary recall and the students' way of reading materials.
Both studies by Lasekan and Godoy (2020); Zhang et al (2018) showed the positive effect of local-based content on language learning skills. In contrast to , who drove the insignificant impact of local-based contents on vocabulary recall. The designed assessment test of  has a few questions, which cannot reveal the difference among students due to the lower discriminatory power of assessment.

Summary of Findings
To sum up; there is a dearth of studies and evidence that emphasized the effectiveness of using local content in teaching the English language as a foreign language (EFL). Nevertheless, not all studies designed and assessed adequately scientifically reading skills. The majority of studies paid attention to comprehension rather than the way of reading, speed of reading, and so forth. The effectiveness of local content assessed at medium to large effect on reading skills. Hence, the language literature is enriched with various descriptive and inferential empirical evidence of local cultural effectiveness. The systematic review reveals a lack of studies on both oral presentation and listening skills. While there is a need to seek writing skills individually in the context of local content.
At all primary, secondary, and higher educational levels, there is a focus on comparing the effect of material orientation on various learning skills in the language. There is a lack of consensus in the research field on which attribute contents label is referred to. The majority of studies referred materials to texts books. Material is the Umbrella term encompassing different genres of content such as audio, text, tasks, and so on.
The preponderance of research is based on the experimental design with specific educational levels and particular proficiency levels. Thus, there is scarce evidence of the effect of the local content on English proficiency. There is a lack of evidence in a local geographical area (i.e.; Arabian and Gulf areas). Observed that east Asian countries are the only geographical area that has interested the researcher and authors.

Conclusion
In conclusion, this review sought the effectiveness of local content in EFL teaching as a holistic -integrative multi-dimension review, which involves various learning domains, i.e., learner skills and learners' psychological aspects. Therefore, culturally related differences among EFL learners should be considered by designers and developers of EFL materials, as well as, teachers in assessing students' acquisition of language.
As such, local cultural contents drew more inference, literal, and elaborative comprehension in both readings and listening. In light of obtained data, the local contents have a medium to large effect on reading and listening skills. As hypnotized, the students who learned through local content exhibited lower anxiety levels, a higher level of attention, confidence, interests, and motivation and scored higher than their counterparts in comprehension, because they engage with familiar names and culturally distant contextual clues, turns to higher acquisition gains and benefits.
The present study revealed a gap in the research field of local cultural materials and a weakness in previous evidence. Future research should include several proficiency levels, gender, educational level, and comprehensive local cultural materials. Materials should not be excluded from textbooks and passages, it is supposed to comprise audio, visual, and written texts combined with communication task and projects. Also, the effectiveness of cultural materials must be further investigated in speaking and writing domains.
Future assessment tests have to comprise more difficult questions and high discriminatory factors to cast a vast outcome and avoid the ceiling effect. Furthermore, studies must detect the mediation and moderating effect of gender, psychological aspects, test type, and topic in investigating differences in learners' acquisition.