Researching English language textbooks: A systematic review in the Chinese context (1964–2021)

Abstract

A new wave of developing English textbooks for compulsory education in China demands for more attention on the integration of textbook research and practice. While increasing research has investigated the design and implementation of English textbooks for Chinese learners, there is a lack of a systematic review on the structural development of this field, leaving prominent research areas, research methods, and enlightening findings unclear. This paper addresses the above issues by systematically reviewing 530 research concerning English textbooks in the Chinese context. As a data-driven study, we applied content analysis and developed a coding scheme, manually annotated all data and cross-checked our annotations. Findings from descriptive statistics and content analysis showed increasing attention on textbooks research from Chinese researchers, inadequate empirical studies, insufficient effort on English textbooks for compulsory education, and three research themes, i.e. textbooks production, textbooks implementation, and textbooks evaluation. Future directions and implications are further discussed.

Introduction

Textbooks as primary learning resources play a pivotal role in teaching a foreign language (Sheldon, 1988; Tomlinson, 2017). Foreign language textbooks not only provide target forms and meanings as language input but also steer cultural and ideological inputs and potentially model learning activities, contributing to developing language competence and inter-cultural communication capability (Xiang & Yenika-Agbaw, 2021; Yuen, 2011).

Educational policies have experienced changes along with the socio-economic development and textbook development generally plays a prominent role in the overall situation of China (Luo, 2019). The central government was the only permitted provider of English textbooks before the mid-1980s when a decentralisation policy was launched to allow local developers to design textbooks. The decentralisation process witnessed the flourishing development of local textbooks with increasing international collaboration. Within the same period of time, a national textbook censorship committee was built in 1986 to ensure the quality and appropriateness of the textbooks.

In recent years, the central government has been engaged in recentralising the production of textbooks, paying particular attention to culture, values, and ideologies. In 2017, the State Council established the National Textbook Committee to guide and coordinate matters concerning national teaching materials. According to the Department of National Textbook of the Ministry of Education in 2020, during the 13th Five-Year Plan period (2016–2020), China has endeavoured to build the so-called ‘Five Systems’ of textbook construction, i.e. (1) a system for leadership and work; (2) a system for planning and managing textbooks; (3) a system for censoring and evaluating textbooks; (4) a system for providing finance, personnel, and infrastructure support; and (5) a system for developing new curriculum and teaching materials. Official statistics have shown that nearly 190,000 kinds of textbooks¹ were used at all levels of education in China at the end of 2020.

Foreign language textbook construction constitutes an essential component in the national textbook construction system. In 2018 and 2020, respectively, the Ministry of Education (MOE) revised and released the curriculum plans and curriculum standards for 21 subjects at senior secondary schools, including six foreign language subjects, i.e. English, Japanese, Russian, German, French, and Spanish. Accordingly, senior secondary school textbooks for these six subjects were revised or developed in alignment with the principles of the curriculum plans and curriculum standards and were approved by the Ministry of Education in 2020. Since early 2019, the curriculum plans and the curriculum standards for compulsory education have been comprehensively revised and was completed in April, 2022. The current textbooks for primary and junior secondary schools are undergoing revisions along with the enactment of the new curriculum plans and the curriculum standards.

At the same time, there is a growing body of international and domestic research on English language textbooks in China (Cheng et al., 2019; Le, 2014; Xiong, 2012; Xiong et al., 2017; F. Zhang, 2012a, 2012b). Many of these works have concerned the principles and processes of material design, investigating both the content and effectiveness of English language textbooks for Chinese learners. The expanding research and the recentralisation education policy demand for an overview of the range and direction of English language textbook research in China. However, there is a lack of a systematic review on such publications. Addressing this issue is important to strengthen the theoretical ground of this field.

In light of the existing research and the Chinese context, this study aims to review the number of publications across time, research methods, textbook publisher, textbook users, and research themes. The number of publications across time provides a reference for the general trend of the development of this field. Research methods reveal the nature of studies, assisting readers in appraising the validity of findings. Textbook users are indispensable to be considered when developing textbooks as the needs of users normally underpin the material design. Textbook publisher could be a factor involved in textbook evaluation in China. For instance, when it comes to compulsory education in primary and secondary schools, textbooks developed by the national publisher normally possess a higher status than those developed by the local publishers and/or international publishers. Finally, latent research themes reflect the major issues and directions of English textbook development in the Chinese context.

In the following sections of this paper, we will introduce the method, including data collection and annotation, followed by presenting and discussing findings of emerging themes. We conclude this paper by summarising major findings and future directions.

Research questions are:

• (1) What does the overall picture look like regarding the number of publications, research methods, textbooks users, textbooks publishers, and research themes?

• (2) Under each research theme, what are the important areas attracting researchers?

Method

This section introduces the procedure of data collection, the development of a coding scheme, and data analysis.

Data collection

Publications on learning English as a Second/Foreign Language (ESL/EFL) teaching materials/textbooks/course books in the Chinese context were collected, including research journal articles and doctoral theses published in English language and Chinese language. Figure 1 displays the search procedure. As part of a bigger project, the collection started from searching keywords in ‘Titles’. The searching keywords for articles in English were: ESL textbook, ESL course book, ESL teaching materials, EFL textbook, EFL course book, EFL teaching materials, English textbook, English course book, English teaching materials; the searching keywords for articles in Chinese were 英语教材 [Translation: English Language Textbooks/Teaching Materials/Course Book]. No time filter was applied, so the time period started from the first relevant publication in 1964 to the time when this study was carried out, i.e. June 2021. The sources of journals included international and local well-established journals listed in the Social Science Citation Index (SSCI) and the China Social Science Citation Index (CSSCI). Book chapters, monographs, and conference proceedings were not included.

Fig. 1

An overview of search procedure

The inclusion criteria concerned the research topic and the source of publication. We selected publications by both automatic functions of Endnote and manual check. For publications in English, the initial search in the databases of EBSCO-Academic Search Complete, EBSCO-ERIC, Elsevier-ScienceDirect Journals, JSTOR, SAGE Journals Online, Scopus, SpringerLink Journal, Web of Science, Wiley Online Library-Journals, and ProQuest: Dissertations and Thesis Global (PQDT Global) provided 1564 results of articles and 102 doctoral theses. We downloaded the citations in Research Information Systems (RIS) format and used the function of Endnote to delete duplicate articles automatically. This step helped us delete 55 references. Then we manually checked the source and the content of abstract and keywords. The source of the article was searched in the Journal Citation Report provided by Web of Science to check whether the journal was indexed in SSCI at the year of publication.

The content of journal was checked by reading its abstract and keywords. Only research on English language teaching materials in the Chinese context were collected. If the place of using textbooks was not in China, the article would not be included. Also, if the topic focused on improving the content of non-English discipline like chemistry, the article would not be included. We kept research on textbooks developed for English for Specific Purposes (ESP), such as medical English or business English, as ESP textbooks focused on English language development rather than the content of non-English disciplines. The same criteria of manual check were applied to doctoral theses. After the manual check, we collected 16 research articles and 13 doctoral theses.

For publications in Chinese, we used the database China National Knowledge Infrastructure (CNKI²) and set the filter of journal source as CSSCI. The initial search showed 561 results of journal articles and 9 doctoral theses. Then we manually checked the content to exclude non-English discipline publications. After the manual check, we collected 492 research articles and 9 doctoral theses. In total, we collected 16 research articles published in English, 13 doctoral theses published in English, 492 research articles published in Chinese, and 9 doctoral theses published in Chinese.

Development of a coding scheme

Figure 2 shows an overview of categories involved in coding. The basic information such as ‘the year of publication’, ‘textbook users’, and ‘textbook publishers’ was straightforward to be extracted. However, to code ‘research methods’ and ‘research areas’ required interpretation. For instance, some studies used surveys to collect data, but the analysis could be carried out on open-ended questions as well as on ratings. In this way, a study using surveys could be a quantitative study or a mixed method study. When coded research methods, we read more on findings and discussions to further determine nature of the study. In the sheet, we labelled the most prominent element stated in the publication, either be instruments like ‘tests’ or analytical procedure, like ‘content analysis’, which was a frequently mentioned analytical approach in qualitative analyses.

Fig. 2

An overview of the coding scheme

Coding research areas also required insights from scholars. Table 1 shows a sub-scheme of coding ‘research areas’. The annotation of the second-layer coding was an iterative process. We read research questions in details to code the research areas. It should be noticed that a single study might have more than one research area, and sometimes several research questions might belong to a single research area. For instance, research questions like Do learners at different educational levels prefer a certain type of cultural content for English textbooks and Do learners at different English proficiency levels prefer a certain type of cultural content for English textbooks dealt with the same issue of learners’ perception of the textbooks. While they were different research questions in a single study, the research area was coded only once as user-based evaluation (the second layer) and textbook evaluation (the first layer).

Table 1 The sub-scheme of coding research areas

As a data-driven study, we developed the overall coding scheme by firstly reading and discussing 20 articles. The first author manually coded all papers in terms of ‘the year of publication’, ‘research methods’, ‘textbook users’, and ‘textbook publishers’. The second author developed the sub-scheme of coding ‘research areas’ and manually coded this category in all papers. Then, we cross-checked our coding and discussed disagreement. We finally reached 100% agreement on all annotations.

Data analysis

The analysis contained descriptive statistics and content analysis (Wells & Moon, 2021; Yuen, 2011). The descriptive statistics reported frequencies of variables, providing a structural overview of each variable to answer research question one. In order to probe into research question two, we integrated descriptive statistical analysis with content analysis. The content analysis is descriptive in nature, aiming at provide a “careful, detailed, systematic examination and interpretation” when identifying “patterns, themes, biases and meanings” (Berg, 2007, p. 303). When investigating research areas, we first labelled each publication. Then we used the filter in the Excel sheet to present publications under the same theme. Extracting major research areas started from scrutinising research aims and research questions. This was followed by scrutinising research findings and synergising implications. Applying content analysis was helpful to retrieve patterns and themes and it added a qualitative perspective to this study, providing more contextual information when interpreting statistical results.

Results and discussions

General findings

General findings address the first research question by showing the diachronic trend of publications and frequencies of research methods, textbook users, textbook publishers, and research themes. As Fig. 3 illustrates, the publications on English textbooks in the Chinese context has undergone a bumpy increasing trend over the past decades. The first blooming period occurred after 1990. Then the number of publications soared from 6 to 18 before another flourishing period around 2010. In 2012, the number reached a peak of 50. It seems that the rising trend of researching English textbooks has been motivated by the decentralisation policy, which has expanded the textbook market. When local educational authorities took on responsibility for administrating the development and production of English textbooks according to the local needs, it is not unreasonable to have more discussions and research on English textbooks. After the peak period, there was a sharp decrease to just one publication in 2016 and a following rising trend in recent years where a re-centralisation process focusing on controlling the ‘appropriateness’ of values conveyed by the textbooks has been formulated by educational policies.

Fig. 3

Number of research publications related to textbooks for learners of English per year – a diachronic trend

Regarding research methods, we found that 295 studies were non-empirical studies that focused on conceptual discussions, whereas 235 studies were empirical research with specified research methods. Among the empirical research, 174 studies adopted qualitative analyses, 45 adopted quantitative analysis, and 16 adopted mixed methods, see Fig. 4. By scrutinising the publications, we found that content analysis occurred most frequently in the method section, followed by surveys, corpus, and discourse analysis. Some mixed-method studies also adopted content analysis, surveys, or interviews and surveys. Tests for examining learners’ outcomes and interviews for collecting learners’ perceptions were also used occasionally.

Fig. 4

An overview of research methods in empirical studies

The review found that more than half of the studies were carried out on English textbooks for university students and adults, with a raw frequency of 335, accounting for 63% of the data (see Fig. 5). Research on textbooks for secondary and primary school students was much fewer, with a raw frequency of 127, accounting for 24% of the data. Research addressing kindergarten children’s textbooks was scarce, only accounting for 1% of the data.

Fig. 5

Frequencies of textbook users

With respect to publishers of textbooks, the review found that apart from 273 studies that did not specify this information; 208 studies investigated national textbooks which were developed with support from the central government, accounting for 39% of the data (see Fig. 6). Research on textbooks developed by local publishers was 43, accounting for 8% of the data. There were 4 studies on textbooks with international publishers, accounting for 1% of the data. The frequencies signalled that nationally developed textbooks were at the heart of research attention.

Fig. 6

Frequencies of textbook publishers

Three research themes emerged from coding research questions: textbook production, textbook implementation and textbook evaluation. Figure 7 shows the distribution. Textbook production and textbook evaluation obtained higher frequencies with raw frequencies of 276 and 249, respectively, signalling that these two themes received more attention than textbook implementation, which accounted for only 11%.

Fig. 7

Frequencies of research themes

Research on textbook production

Under the theme of textbook production, eight major issues were derived from research questions and objectives. As shown by Fig. 8, the most frequently discussed issue was the design blueprint for writing English textbooks for Chinese learners, with a raw frequency of 157, accounting for 57% of all publications. Then, there were issues related to problem–solution, contents, and principles, with a frequency of 56 (20%), 25(9%), and 21(7%), respectively. Other issues, such as material selection, process, localisation, and factors influencing production, overall contributed to around 7% of the data.

Fig. 8

Frequencies of research themes related to textbook production

Due to the space limitation, here we discuss studies on blueprint, problem–solution, contents, and principles, accounting for 93% of the data. The issue of blueprint generally focused on how English textbooks for tertiary level education should be constructed considering the dynamic changes of different eras. A common change lies in the change of education policy. It is observed that in the 1990s, research mainly focused on the development of English textbooks for English major students in Chinese universities (Wu, 1999). During the period 2000–2010, researchers spent a great deal of effort discussing changing principles in the approach to writing English textbooks, arguing that they should be guided by teaching and learning theories (Fan, 2000), such as Social Interactionist Theory (Vygotsky, 1978). The following decade witnessed flourishing discussions on developing English textbooks for specific purposes, such as business (Cai, 2006), medicine (Le, 2014), and travelling (Zeng, 2014). During 2010–2020, there was also increasing research on deploying multi-media into classroom teaching, inviting a new trend of implementing blended learning (Chang, 2013). The high frequencies of conceptual discussions implied that Chinese scholars’ opinions on the overall picture of constructing English textbooks might be necessary for textbook writers and practitioners.

Research on themes related to problems and solutions discussed issues in published English textbooks and provided plausible suggestions. Most of these textbooks were designed for university students, ranging from English major students to other majors, such as travelling and law. A few empirical studies pointed out problems based on case studies of English textbooks (Zhang, 2001) and/or interviews with instructors/students (Wang & Ren, 2002). Problems advanced for general English textbooks concerned the development of communicative abilities and cultural awareness (Zou, 2013), whereas problems for ESP textbooks focused on insufficient professional knowledge about the subject in English (Zhang, 2012a, 2012b). Proposed solutions recommended that teachers needed to focus more on students’ needs and cultivate students’ inter-cultural competence.

Research on contents discussed specific issues in textbook design, such as the design of tasks (Wang & Guo, 2008), the integration of cultural elements (Li, 2007), and the implementation of technology (Lee, 1964). Among these discussions, integrating Chinese culture into English textbooks and using technology in teaching were two key topics from 2010 to 2020.

Similar to discussions on problems and solutions, the issue of principles for developing English textbooks was explored for both textbooks for English Majors and ESP textbooks, emphasising the latter type. This emphasis might be due to the problem of relatively fewer resources and development of ESP textbooks, compared with textbooks for English Majors in China. They all focused on textbooks for university students or adults. The proposed principles generally concerned consistency, cultural awareness, and communicative abilities.

Research on textbook implementation

Compared with textbook production and evaluation, very limited attention has been paid to textbook implementation, with a raw frequency of 62 in total. Within the limitations of our selection criteria for published research, most attention has been paid to how teachers utilise textbooks (see Fig. 9). The investigation from the perspective of how learners use textbooks and how textbooks are deployed in classroom teaching or embedded in a specific program is scarce. This might be due to a lack of awareness of learners’ autonomy in the history of Chinese education, where the Confucius philosophy highlights the paternalistic role of teachers in learning.

Fig. 9

Frequencies of approaches to textbook implementation

The studies on textbook implementation by teachers showed two main areas of interest. The first one is exploring effective teaching pedagogy based on the English textbooks in use. These studies cover both non-empirical discussions referring to certain textbooks and empirical investigation on teachers’ beliefs and learners’ comments on teaching practice through surveys, interviews, and case studies (Liu & Liang, 2014; Wong, 2015). The second area seems to be policy-motivated studies as more additional factors other than the textbook itself were included in research on teachers’ practice. For instance, increasingly, research has focused on the changes in understandings of how English textbooks might be implemented, the incorporation of technology and English textbooks, and the integration of moral values and Chinese culture into English textbooks. In the broader context, the recent education policies have been reforming the official English textbooks, placing more attention on developing key competencies regarding values and culture and English language competency.

Only two studies on textbook implementation by learners were found. Both studies were empirical research collecting learners’ perceptions on using English textbooks. Hui and Hu (2021) surveyed 50 primary school students from Xi’an in China, with 25 girls and 25 boys from grade Four and found that textbooks were metaphorically perceived as authorities, resources, tools, and companions. Wang (2012) surveyed 161 English postgraduates in Shanghai and generated an overview of how these postgraduates used different types of English textbooks.

A few studies investigated textbook implementation in classrooms and programs. Some of these studies concern factors influencing using textbooks, such as the underdeveloped economy and local culture (Luo & Xu, 2011) and perceptions of new technology (Liu & Ren, 1995). Other studies explored effective ways to design class activities or teaching programs to use the textbooks more effectively.

Research on textbook evaluation

The theme of textbook evaluation contains four categories, i.e. content-based evaluation, user-based evaluation, learning-based evaluation, and developing evaluation instruments. As shown by Fig. 10, content-based evaluation received the most attention from scholars, with a raw frequency of 193, accounting for 77% of the whole data. User-based evaluation and developing instruments had similar frequencies, with frequencies of 24 (10%) and 22 (9%), respectively. The learning-based evaluation had the lowest frequency (10, 4%).

Fig. 10

Frequencies of categories for research on textbook evaluation

Research on content-based evaluation contains perspectives from macro-evaluation, such as the extent to which the content of a textbook fulfilled the curriculum requirements, and perspectives from micro-evaluation, which deals with a specific aspect of the content, such as culture and ideology, the historical reviews, the multimodal design, and the language component. The perspective of culture and ideology revealed the lack of Chinese culture in English textbooks and discussed how to integrate local culture in appropriate ways. For instance, some empirical analyses on English textbooks pointed out that western cultures were represented more frequently than Chinese culture and most of the content was not in-depth (Huang, 2019; Yuen, 2011; Zheng & Chen, 2015). The lack of Chinese culture and tradition representation might lead to less competence in describing local cultures, impeding inter-cultural communication. The more recent discussions focused on arousing the awareness of political and virtuous appropriateness when developing English textbooks (Liu et al., 2021).

Research providing historical reviews generally displayed how English textbooks have been developed and the shifts of focuses during different phases. Most of these reviews were carried out on developing official English textbooks for university students. Scholars reviewed the development across different time periods, dating back to the late Qing Dynasty or the establishment of People’s Republic of China in 1949. Liu (2011) summarised five stages: (1) relying on imported English textbooks in the late Qing Dynasty; (2) developing domestic English textbooks in the Republic of China era; (3) state-controlled textbooks; (4) developing diverse and systematic English textbooks after the reform and open policy; (5) the booming of imported and localised textbooks in the twenty-first century. Liu et al., (2011) pointed out essential principles in writing materials, such as considering Chinese students’ cognitive development and psychological needs and cultivating intercultural communication competence.

Studies on the multimodal design of textbooks and the language component evaluated the extent to which the linguistic and visual resources were selected appropriately (Chen, 2010; Guo & Feng, 2015; Song, 1991). A number of studies proposed the issues of limited vocabulary range and lacking pragmatic knowledge in English textbooks for Chinese learners (Sun & Thi Ngoc Yen, 2020; Yang, 1988).

Unlike content-based evaluation, research on user-based evaluation focused on perceptions of textbooks from teachers and learners. Through surveys and interviews, the advantages and disadvantages of certain English textbooks were collected from teachers and learners. The research found that most users were satisfied with the English textbooks regarding the general design and the content (Guo & Xu, 2013). However, some issues were also revealed from low satisfactory scores towards the design of exercise and less confidence in maintaining the interest.

Studies on developing evaluative instruments were all non-empirical discussions, advancing opinions that the evaluation criteria shall be consistent with the curriculum, teaching objectives, and learners’ needs.

Learning-based evaluation concerned the learning outcome from experimental studies (Li & Tian, 2010; Shanghai primary & secondary school English textbook developing group, 1996). Different sets of English textbooks were implemented in schools as teaching experiments, with results often showing that the newly developed English textbooks generated better learning results.

Discussion

To summarize, our study found an overall increasing trend of publishing English textbooks in the Chinese context over the past decades. Less than half of these publications were empirical studies. Among these empirical publications, about 74% research adopted qualitative analyses. For textbook users, 63% textbooks under investigation were designed for English textbooks for university students and adults, whereas limited attention was paid to textbooks for secondary and primary school students and kindergarten children. Most research investigated textbooks developed with support from the central government.

There were three major themes emerged from the data: textbook production, textbook implementation, and textbook evaluation. Textbook production mostly concerned the design blueprint. The discussions witnessed a shift from designing textbooks for English major students to designing ESP textbooks. Textbook implementation received the least attention compared with other two themes. Most of the investigation focused on textbook implementation by teachers, leaving students’ perceptions underexplored. Textbook evaluation concerned more about the extent to which the content of a textbook fulfilled the curriculum requirements or evaluating a specific aspect of the content. In recent years, the discussions focused on arousing the awareness of political and virtuous appropriateness. However, empirical evidence was scarce in textbook evaluation.

Given the increasing scholarly effort on researching English textbooks and the significance of developing them for foreign language education in China, it may be helpful to advance a research agenda for this field to support its development.

In the first place, the research methods require more attention from scholars to ensure the validity of findings. Empirical studies appeared to be less than non-empirical studies in this field. The non-empirical studies generally discussed concepts and principles for developing textbooks, whereas the effectiveness of textbooks could hardly be evaluated from such discussions. To develop this field, more empirical evidence should be collected from studies with rigorous design. For instance, Shanghai primary and secondary school English textbook developing group (1996) was such an empirical attempt in comparing two sets of textbooks and providing pedagogical suggestions. Among the empirical studies, there were limited quantitative studies and mixed methods studies, suggesting another direction that needs more attention. For example, data analytics could be, therefore, exploited more to gauge the latent generalizable patterns across large data sets (Tay & Pan, 2022).

With respect to textbook users, textbooks for secondary and primary school students lack sufficient investigation. In China, secondary and primary school education is compulsory, playing a fundamental role in student’s development. In recent years, the central government has launched important policies to promote compulsory education. However, this review found that 63% of publications investigated textbooks for university students and adults, leaving the research on compulsory education underexplored. The discrepancy between the progress of research and the requirements of practice urges more attention from scholars. Exploring the designing principles, language features, and cultural values in English textbooks for secondary and primary school students will be helpful to gauge pedagogical suggestions for textbook developers.

Our review of research areas also pointed out that research on textbook implementation appears to be very limited. There were some studies on how teachers made use of textbooks. Studies from the perspective of learners are also important to maximise the benefits of textbooks, yet scarce in our data. Along with the shift from teacher-centred classrooms to students-centred classrooms, understanding the students’ perceptions of textbooks and habits of using them may reveal learning needs that are crucial to designing materials and syllabus. The underlying reason for the limited studies on textbook implementation and the students’ opinions might be twofold. On the one hand, textbook implementation research normally requires empirical designs to collect evidence, which might demand collaborations between practitioners and researchers. This appears to be challenging for some practitioners who were the authors of domestic publications as they might have limited access to systematic and formal research training. On the one hand, the long and profound influence of Confucius philosophy emphasises the higher status of teachers over students in classrooms. Teachers’ authority has long been reinforced in Chinese culture, which might lead to the overlook of students’ autonomy. Although the education policies are promoting learners-centred classrooms, it takes time to facilitate the change.

Conclusion

This paper reported a systematic review of 530 research on English language textbooks in the Chinese context. By investigating the basic information of each publication, such as publication dates, research methods, textbook users, textbook publishers, research themes, we provided an overall picture of this field. By analysing the abstracts, content, and findings of publications, we detected underexplored areas for textbooks researchers and suggestions for textbook development.

Scholars interested in researching English textbooks for Chinese learners could consider designing empirical studies on textbooks for secondary and primary school learners. More attention on learners’ perspective is needed. In light of existing studies (Huang, 2019; Yuen, 2011; Zheng & Chen, 2015), textbook designers could consider more about how to balance the representation of Chinese cultures and foreign cultures, with more materials representing cultures and values that are important for the Chinese society. Materials providing pragmatic knowledge are also helpful to assist in language acquisition in the social context (Sun & Thi Ngoc Yen, 2020; Yang, 1988). When designing the learning activities, especially exercise in the textbook, learners’ attributes at different stages of cognitive and psychological development cannot be overlooked (Liu et al., 2021).

This study is not without limitations. Our data only included original research articles and the doctoral theses available from the database of ProQuest: Dissertations and Thesis Global. Book chapters and monographs on this topic were not included. Future studies could expand the scope.