What factors affect teacher professional learning: a qualitative meta-analysis based on the Onion model

Abstract

Purpose

Current academic research on teacher learning is increasing in number and deepening in quality, but at the same time, the heterogeneity is growing significantly. Similar work is challenging to cross-check regarding conclusions due to the different research foci. This paper aims to provide a reliable theoretical framework and offers solid insights based on the existing research.

Design/methodology/approach

Based on the Onion model, 67 core literature in English and Chinese were coded through qualitative meta-analysis methods to explore environmental, behavioral, competence, belief, identity, mission and other factors that may impact teacher learning.

Findings

It was found that the quantitative structure of the current relevant studies was in an inverted triangular shape with three levels of steps, respectively, which can be summarized as structural environment, core behaviors and dominant mission. The heterogeneity between the findings mainly originated from two situations, oppositional and complementary and some structural adjustments were made to the Onion model according to the coding results to better represent the interaction of influences between the levels. It also analyzes current research trends and the centrality of learned behaviors based on the coding results.

Social implications

The design of teacher learning activities should combine theoretical, practical and inquiry learning to ensure that teachers are kept fresh and motivated by sustained and varied stimuli.

Originality/value

To the best of the authors’ knowledge, this study is the first to analyze teacher learning influences through qualitative meta-analysis and create node saturation to analyze the results, resulting in highly credible and valuable research findings.

Citation

Li, H. (2024), "What factors affect teacher professional learning: a qualitative meta-analysis based on the Onion model", Quality Education for All, Vol. 1 No. 1, pp. 142-157. https://doi.org/10.1108/QEA-03-2024-0028

1. Introduction

Teacher learning, a pivotal aspect in a teacher’s professional journey, encompasses continually refining knowledge, honing competencies and cultivating literacy throughout their career. Unlike primary education, which primarily emphasizes theoretical knowledge accumulation, teacher learning, as a form of adult education, transcends mere knowledge acquisition. Its essence lies in fostering problem-solving skills, cultivating the capacity to comprehend complexities and fortifying competencies (Candy, 1991). This fundamental distinction underscores the unique factors influencing teacher learning compared to K12 education for adolescents. Against educational reform imperatives and societal progress, teacher learning has emerged as a focal point in contemporary educational discourse. Its significance extends beyond individual pedagogical prowess to encompass broader educational quality enhancement goals. Recent scholarly inquiries into in-service teachers’ learning determinants have yielded notable insights. Korthagen (2017) posits that teacher learning, predominantly unconscious, operates along three interlinked dimensions:

1. cognitive;

2. affective; and

3. motivational.

Contrarily, Pinar et al. (2021) and Chen and Chen (2022) advance divergent perspectives, underscoring the pivotal roles of peer feedback, teacher–student dynamics, motivational impetuses and belief systems in shaping teacher learning trajectories. Furthermore, scholars have tried conceptualizing teacher learning competencies through integrated research methodologies (Huangfu and Jin, 2021). Moreover, disciplinary variances and contextual nuances necessitate nuanced approaches to professional development models (Harris et al., 2009; Mercader and Gairín, 2020), urging researchers to appreciate the intrinsic disciplinary idiosyncrasies inherent in the teaching profession.

The principal determinants impacting teacher learning outcomes have evolved depending on the study objectives and research methodology. Leadership is increasingly recognized as pivotal in the learning process (Fairman et al., 2023; Hendawy Al-Mahdy et al., 2024), while professional learning communities are also acknowledged for their significant influence on teacher learning (Prenger et al., 2021; Toom et al., 2021). Despite similar endeavors, studies may diverge in conclusions due to disparate research focuses. Notwithstanding comprehensive investigations akin to Hayes et al.’s (2024), elucidating the factors contributing to variations in teacher learning through an integrated model of professional growth across activity domains, personal domains, practice domains and outcome domains, extant research findings are burgeoning, potentially resulting in biased policy resource allocation owing to a lack of focus in practical application, thereby impeding their practical utility. Qualitative meta-analysis, as an emerging research methodology with methodological integrity, can synthesize heterogeneity, thereby offering coherent and lucid novel insights amidst complex studies (Levitt, 2018), thus rendering it applicable to the research question in this paper. The “Onion Model”, an earlier theoretical framework of teacher development, encompasses a wide array of factors potentially influencing teacher learning and has undergone rigorous theoretical and empirical scrutiny (Leatemia et al., 2022; Ashraafi et al., 2020), boasting strong inclusivity and scalability. Thus, this paper aims to synthesize extant literature on factors affecting teacher learning based on the Onion model through a systematic qualitative meta-analysis and scrutinize the structure and variances in their conclusions, thereby furnishing robust theoretical underpinnings for subsequent inquiries.

2. Research methodology and Onion model

2.1 Methodology

The quality of selected studies in qualitative meta-analysis is a pivotal criterion, necessitating exhaustive search criteria and steps (Leary and Walker, 2018). This study undertook a qualitative meta-analysis encompassing Chinese and English core papers on factors influencing teacher learning published between 2013 and 2023. The literature search comprised two phases: a Chinese search and an English search. Initially, the Chinese literature search predominantly used the Chinese National Knowledge Infrastructure database, using keywords such as “teacher learning,” “teacher professional development,” “influencing factors” and “impact,” targeting journals indexed in the Chinese Social Sciences Citation Index and its extended version. Additionally, the Wanfang database was consulted to supplement the search. Conversely, the English literature search primarily leveraged the Web of Science database, using keywords such as “teacher learning,” “teacher professional development,” “influence factor” and “influencing,” focusing on journals indexed in the Social Sciences Citation Index. Subsequently, Google Scholar was used to augment the search outcomes.

Following the initial search phase in both languages, the retrieved literature underwent meticulous screening. Publications not aligning with the study’s objectives were excluded, while the remaining pertinent literature underwent quality assessment and content coding. The recorded information encompassed the literature’s title, publication journal, study objectives, research methodology and survey conclusions (conclusions are extracted only in the abstract, discussion and conclusion sections and are synthesized by reading through the entire text to determine if the factor has an impact on teacher learning). The findings of each study were systematically segmented into various nodes for incorporation into the coding framework, with emphasis placed on omitting viewpoints deemed inconsequential to teacher learning, thereby ensuring alignment with the node directions. The coding framework adopted for this study adhered to the Onion model delineated by Korthagen (2004), which classifies influences on teachers into six hierarchical levels: environment, behavior, competence, beliefs, identity and mission (refer to Figure 1). Nodes that could not be accommodated within the existing framework were categorized as “other factors” per coding requirements.

Following the completion of coding, node deduplication is executed. This process entails a meticulous review of the practical literature, wherein each coded entry is scrutinized to discern its nuanced connotations. Consequently, redundant nodes are identified and subsequently eliminated, yielding a refined set of coding outcomes characterized by heightened relevance and independence. This de-duplicated coding compilation is a comprehensive reference list, delineating intricate impact factors pertinent to this study stage. Concurrently, a comparative analysis is conducted between the de-duplicated coding results and the original coding to ascertain the trajectory for future research endeavors. The author independently conducted the literature retrieval and coding processes, ensuring consistency in the criteria for literature extraction and the connotations of coded nodes. This methodological rigor enhances the reliability of the study.

2.2 Onion model

The Onion model, introduced in the early 21st century, serves as a theoretical framework for comprehending and advancing teacher education. Comprising multiple layers, each layer delineates distinct factors impacting teacher behavior and progression. The outermost layers encompass observable elements – environment and behavior. The environment denotes the educational and living milieu wherein teachers operate, while behavior signifies specific actions exhibited during the teaching and learning process. Subsequently, the competence layer follows, encapsulating knowledge and skills indicative of behavioral potential. Teachers’ competencies dictate their demonstrable behaviors, which, in turn, are shaped by underlying layers of beliefs.

The beliefs layer serves as the internal impetus driving teachers’ actions. Their educational outlook, student expectations and conceptualization of their professional roles influence both behavior and competency evolution. Beneath lies the identity layer, encapsulating teachers’ perceptions of their professional persona, encompassing self-identity and roles, as well as their professional identity’s integration into their self-concept. At the most profound level lies the mission layer, delving into teachers’ personal values and life aspirations, constituting a wellspring of intrinsic motivation and a pivotal realm of teacher development. This dimension closely intertwines with teachers’ fundamental values and aspirations. Interactions and influences permeate these layers, fostering bidirectional interactions between inner and outer strata that shape individual teacher development trajectories. While the outer layers – such as environment and behavior – are readily observable, the inner layers – like beliefs, identity and mission – lack direct observability. The Onion model furnishes a comprehensive perspective for comprehending and enhancing teacher quality, underscored by holistic development from within rather than mere enhancement of behavioral pedagogical skills through skills training.

3. Literature search and coding results

In this study, the initial search in the Chinese literature search section retrieved 43 papers, from which 27 valid documents were identified after screening. In the English literature search section, the initial search yielded 80 papers, of which 40 valid documents were selected after filtering. The combined total of valid papers from both English and Chinese sources was 67, resulting in an efficiency rate of 54.4%. The researcher conducted the coding independently to ensure the homogeneity and validity of the coding results. Saturation is defined as the ratio of the number of nodes not de-duplicated to the number of nodes de-duplicated, with a minimum value of 1. The formula is:

SSaturation=NNodes (not de−duplicated)NNodes (de−duplicated)

This metric can indicate the robustness of research about this factor within an autonomous and self-contained literature cluster. A higher value within the research field implies greater research content adequacy, enhanced conclusions homogeneity and elevated comprehensive reliability. Conversely, a lower value suggests the presence of unexplored nodes within the field, thereby indicating the tremendous potential for discovery and heightened research value. The detailed decoding outcomes of Chinese and English literature are delineated in Tables 1 and 2, respectively, while the pertinent statistics regarding research methodologies and saturation levels are presented in Table 3.

4. Analysis of coding results

The coding outcomes derived from this investigation resonated well with the Onion model framework on the whole, as the total node count generally aligned with the prognostications of said model. Nevertheless, within the coding endeavor, it surfaced that specific nodes eluded categorization within the pre-established framework. These encompassed diverse personal variables, notably age, gender and marital status, potentially influencing teacher learning. Despite their limited incidence and deviation from the Onion model’s purview, grappling with their integration proved challenging, prompting their classification as “other factors” within this inquiry. Beyond these supplementary factors, the primary structure of the Onion model predominantly assumes the configuration of an inverted triangle featuring three hierarchical tiers.

Furthermore, we observe notable disparities in the focal points of Chinese and English studies within teacher learning. This contrast is particularly evident in the emphasis placed by English studies on the intrinsic characteristics of teachers themselves, such as age and gender, among other factors. In contrast, Chinese studies tend to prioritize attributes attributed to teachers by their surrounding environments, including income, marital status and occupational rank, among others. This discrepancy likely stems from the predominantly administratively oriented social milieu in China, where a pervasive belief exists that an individual’s social standing and role are closely aligned with their competence. In contrast, research environments in Western contexts may exhibit a comparatively weaker administrative culture, thus facilitating deeper investigations into individuals’ intrinsic qualities and competencies rather than focusing solely on external conditions imposed by society (Lomas et al., 2023).

Consequently, this disparity manifests in variations in the quantity and depth of research conducted at the belief level between these two cultural contexts. Because beliefs constitute the core of the outermost layer, researchers are urged to pay greater attention to individuals’ inherent characteristics. However, the Chinese socio-cultural context often overlooks this imperative, resulting in insufficient depth in related research endeavors. Despite these disparities, the overall corpus of Chinese and English literature does not fundamentally diverge in terms of its constituent nodes.

4.1 Heterogeneity analysis of coding nodes

Heterogeneity within meta-analyses pertains to the distinctions among the included studies and is nearly inevitable in such analyses. This variability is particularly pronounced in qualitative meta-analyses, wherein attaining a uniform and consistent data structure akin to traditional quantitative meta-analyses is challenging owing to the data’s diverse, intricate and often unquantifiable nature and findings. Consequently, a pressing need arises for thorough elucidation of coding heterogeneity, with an explicit focus on explicating the associated variability in findings, which serves as one of the primary objectives of this study.

In developing this closed literature clustering, we have observed that the heterogeneity within the literature primarily arises from contradictory and complementary research findings. Divergent research conclusions often result from variances in the research methodologies used. In the typical quantitative research course, researchers tend to focus on specific factors or those deemed to exert a noticeable influence on learning. They formulate preinvestigative hypotheses and delineate potential conclusions based on documentary evidence, empirical observations and other pertinent sources. However, through rigorous investigation and analysis, certain hypotheses may be invalidated, leading to the determination that particular factors do not significantly impact teacher learning under specific circumstances. Such occurrences are common in quantitative research endeavors. For instance, Huang (2021) noted that teaching efficacy and self-orientation exhibited no discernible impact on the professional development of ethnic minority teachers from the standpoint of field theory. In contrast, mainstream qualitative research typically avoids making assumptions about conclusions, allowing interviewed teachers greater freedom to express their perspectives. The data garnered are characterized by a higher degree of openness and subjectivity compared to quantitative research, making it challenging to ascertain information regarding factors that do not affect their learning. Consequently, the conclusions drawn from qualitative studies are more prone to conflict with those derived from quantitative studies on the same subject matter.

Moreover, divergent interpretations of the same factor across related studies can contribute to heterogeneity to a certain extent, manifesting as complementary conclusions. For instance, Wang (2016) posits that the restructuring of local universities will exert a notably adverse effect on teachers’ professional development, whereas Blackwell et al. (2016) contend that the support provided by schools will foster positive outcomes for teachers’ development. These contrasting viewpoints, representing two distinct interpretations of the environment as a contributing factor, underscore the intricate nature of environmental components. It is foreseeable that a broader array of factors will exert diverse influences on teacher learning, surpassing the capacity of a simplistic polarized assessment framework. Devising a theoretical framework that seamlessly accommodates all factors and directions poses a formidable challenge. Nonetheless, given teachers’ status as open systems, the interplay of these diverse interpretations will engender unpredictable learning trajectories, guiding educators to adapt to various teaching environments and aspire to become “the best teacher for themselves” rather than merely conforming to the dichotomous categorizations of “good” or “bad” teachers.

Heterogeneity can exert a significant influence across a broad spectrum of meta-analytical endeavors, and within this study, the presence of conflicting findings can significantly impact the coding process. To address the conflicting sources of heterogeneity, we omitted factors that did not significantly impact learning, omitting them from the coding framework. While this approach may marginally diverge from the actual findings, the reliability of the coded content in relation to the objectives of this study is maintained. Conversely, complementary sources of heterogeneity represent a facet of the diverse interpretations of the findings and, by their inherent nature, do not influence the trajectory of the study’s coding. Consequently, they do not necessitate additional treatment of complementary sources.

4.2 Structural environment

First, the environment situated at the foundational tier of the hierarchy, characterized by the field of study boasting the highest node count, emerges as a pivotal determinant acknowledged by academics for its impact on teacher learning. Consequently, investigating this environment is deemed imperative and warranted, a notion reinforced by the persistent saturation of literature within the domain despite the extensive node count. The coding outcomes generally echoed the initially structured categorization of teacher development environments posited by Gu et al. (2014), delineating individual environment, school environment and sociocultural environment. However, the author contends that several nodes resisted alignment with the classification as mentioned above, such as “variations in disciplines and institutions” and “tacit knowledge”, alongside other factors encompassing subject-specific knowledge-based elements and the like. Other broad personal environmental factors are classified in the Onion model as being within several cognitive levels, and the environment as a whole shows a clear structure and regularity.

Based on the coding results, apart from the typical categorization of learning environments, the proportion of educational technology used in learning environments rapidly increases with the deepening of research. Therefore, it is necessary to analyze its typical characteristics separately. As early as the 20th century, scholars have discussed the influence of educational technology on teacher development (Brooks and Kopp, 1989). With the onset of the technological explosion in the 21st century, various technologies have been successively applied to the field of education and abstract concepts such as technological philosophy (Forret et al., 2013) have also been studied in an educational context. The most significant technological and environmental factor affecting teacher learning is online educational technology, which has rapidly developed in recent years to adapt to the trend of distance and online education (Macià and García, 2016). It can be predicted that future research on the application of educational technology will be even more important than the current environment, and the research focus will inevitably shift to the practical application of extensive language model technology in the field of teacher education. This will further promote research on educational technology in areas such as artificial intelligence ethics.

Based on the analysis mentioned above, the structure of the environment can broadly be delineated into the following components: individual environment, school environment, socio-cultural environment, technological environment and other environmental factors. This structural connotation differs from the notion of a fixed learning environment constructed to achieve “natural growth” as proposed in humanistic learning theories (Rogers and Freiberg, 1970); instead, it is dynamic and natural. Each element within the environment is interrelated, forming a closely interconnected whole with the teachers themselves and the various factors within the environment do not strictly adhere to a hierarchical structure. Consequently, their influence on teachers is nonlinear. Specifically, the impact of each independent factor on teachers depends on the teacher's perception of that factor. For instance, within an Eastern cultural environment, teachers and researchers perceive administrative events (such as job rotation exchanges or the transformation of local undergraduate institutions) more prominently, exerting a relatively more significant influence. Conversely, within a Western cultural environment, teachers perceive personal factors (such as occupational stress or job characteristics) that are more closely linked to themselves more prominently. Objectively, environmental factors affect teachers to varying degrees, as any influence on individuals will inevitably affect learning. Factors that are more salient to teachers’ perceptions should thus be prioritized for research.

4.3 Core behaviors

The subsequent tier in the hierarchy encompasses behavior, competence and beliefs. These three domains collectively harbor a large number of nodes and occupy an intermediary position within the overarching model. Teacher behaviors encompass the verbal and nonverbal actions, as well as attitudes exhibited during instructional activities, which are shaped by their competencies and beliefs (Pan and Chen, 2023). The study of teacher behavior proliferated during the dominance of behaviorist psychology; however, with the ascendancy of humanism and constructivism, there has been a shift toward a greater emphasis on competence and beliefs within behavioral research, as evidenced by the preponderance of relevant nodes. Teachers’ beliefs, a burgeoning area of inquiry in recent years, encompass various aspects such as educational philosophy, pedagogical approach, perspectives on learning, subject matter understanding and assessment methodologies. These beliefs form cognitive frameworks that inform and shape teachers’ instructional decisions and behaviors, exhibiting a relatively stable and covert nature. Unlike competence, which provides a foundational underpinning for behavior, beliefs profoundly influence behavioral research, dictating the choices and trajectories of teachers’ actions and directly impacting learning behaviors. Consequently, achieving a high level of reliability in teacher behavioral research necessitates a thorough examination and interpretation of beliefs alongside behavior.

The utilization of behavior as a central focal point in modeling and related research endeavors has witnessed a noticeable surge in recent years (An et al., 2023). The coding outcomes of this study reveal a noteworthy evolution in the concept of “behavior”, transcending its erstwhile confinement to physical and tangible bodily actions prevalent at the outset of the century. Instead, there is a discernible trend toward mentalization, whereby abstract psychological behaviors such as reflection (Xu et al., 2023) and innovation (Gkontelos et al., 2023) are now being integrated into the overarching framework of “behavior”. This theoretical shift has broadened the scope of teachers’ behavior beyond mere instructional actions within the classroom, encompassing a spectrum of intricate and multidimensional psychological and social behaviors. Despite shifts in definition, the fundamental dichotomy between the external environment and the internal individual persists, delineating how various environmental stimuli impact the individual teacher. According to Korthagen’s (2004) perspective on teacher development, the concept of “behavior” occupies the outermost layer of the individual teacher, with changes occurring at the cognitive level of the teacher ultimately reflected in observable behaviors. In essence, if cognitive influences fail to precipitate discernible alterations in outward learning or teaching behaviors, their impact remains inconsequential. While ongoing research blurs the boundaries between the external objective environment and the internal subjective milieu, thus challenging the well-established hierarchical structure of the Onion model, behaviors situated at the nexus between the individual and the environment should retain their position at the model's core.

4.4 Dominant mission

Finally, within the tripartite framework of identity and mission, the central component of the Onion model, lies deeply personal and subtle knowledge and perceptions, resulting in a relatively sparse body of research pertaining to identity and mission. Despite the considerable attention devoted to the exploration of teacher identity, the majority of studies have tended to focus solely on identity in isolation. Consequently, these studies have yielded conclusions that lack implications for teacher learning or development and, notably, fail to establish correlations with observable teacher behaviors (Nazari and Karimpour, 2023); thus, much of the literature has been excluded from the coding process. Teacher mission represents an inherent facet of professional learning among educators. It serves as a guiding principle that inspires teachers to continuously pursue the essence and significance of education, facilitating their self-actualization and societal contribution. Situated at the nucleus of learning, the teacher’s mission encompasses intrinsic motivation, a sense of duty and unwavering commitment, constituting the most intricate aspect to unravel and dissect.

The discourse on the mission of teachers can generally be traced back to the mid-19th century (Mather, 1856), during which perspectives on mission bore a distinct religious hue, positing faith and truth as pivotal tools for pedagogical success – a viewpoint now largely disavowed by most educational scholars. In recent years, the rise of holistic perspectives has similarly influenced research on teacher mission, whereby the concept of mission is no longer considered in isolation but is typically studied in conjunction with other factors of teacher development to yield more meaningful insights (Frányó and Sándor, 2024). From the vantage point of the coding nodes in this study, current research on teacher mission predominantly centers on the drivers and guiding principles of teacher development and pedagogy. Due to historical reasons, Western studies on mission tend to intertwine with religious inquiries (Sultmann and Brown, 2019; Branson et al., 2019), while Chinese research leans toward analyzing objective phenomena devoid of conspicuous religious inclinations (Zheng et al., 2023).

A salient feature of mission-related research lies in its multidimensional influences. Studies at the environmental and behavioral layers tend to favor point-to-point linear effects (Korthagen, 2010). In contrast, most research at the mission layer contends that mission interacts with multiple diverse developmental factors simultaneously, particularly in the realm of identity formation (Ottenhoff-de Jonge et al., 2022). This underscores the dominance of mission and highlights a limitation of the Onion model, as its structure inadequately captures such interactive factors – a limitation that will be addressed subsequently. The process of constructing teacher identity is likewise intertwined with the construction of mission; to a large extent, the conclusions drawn from studies on both can be mutually interchangeable. Disruptions in the process of constructing teacher identity can detrimentally impact teachers’ identification with mission, potentially leading to their withdrawal from the field of education (Chong and Low, 2009). In summation, analyzing the mission layer necessitates transcending its simplistic depiction as an isolated stratum; rather, it entails delving into the holistic developmental trajectory of teachers, permeating through preceding layers of development and systematically peeling away the layers of this “Onion” to reveal the comprehensive process of mission formation.

4.5 Structural adjustment based on the Onion model

While the distribution of studies across the various levels of the Onion model may appear uneven, a dichotomous amalgamation of cognitive levels, other than the environment, into a singular level suggests a balanced representation of current research between the external environment and internal cognition. Furthermore, a cursory examination of findings from the learning environment section underscores the discernible structure of the external environment, which influences teachers' learning behaviors akin to that of cognition, enabling scientific clustering and differentiation. However, delineating hierarchical distinctions within the environmental domain poses challenges due to discrepancies between the structural nature of the environment and the hierarchical framework of the original Onion model. Findings reveal a blend of subjectively evaluated environments (such as the pressures and responsibilities of teaching) and objectively typical environments (such as the teacher’s institution). Consequently, a modular approach to distinguishing environmental hierarchies appears warranted amid the consensus that the external environment impacts learning behavior. For instance, Zagallo et al. (2019) differentiate external environments into modules such as the teacher education system, teacher management system, teacher evaluation mechanism, theory and organization of teachers’ professional development, teacher culture and societal values. Unlike the traditional hierarchical structure of the Onion model, this modular distinction allows for bidirectional influence between modules, eschewing distinctions between upper and lower levels and delineates a more intricate pattern of internal influence beyond linear causality. Consequently, this approach offers a comprehensive overview of the characteristics and nuances of the objective environment.

In contrast to the external environment, characterized by a loosely structured objectivity, the interconnection among various levels of cognition within the individual is notably tighter, constituting a cohesive structure of interaction and interdependence marked by intricate dynamics (Zhu and Gao, 2017). Within the framework of the Onion model, the behavioral layer serves as the focal point of impact, with the influence exerted by each level ultimately manifested in behavioral changes. Environmental circumstances and personal competencies constrain a teacher’s generation of learning behavior, which subsequently undergoes feedback, manifesting as alterations in the layers of competence, belief, identity and mission. These changes, in turn, yield unpredictable effects on subsequent learning behavior, thereby engendering a behavior-feedback loop. All influences are subject to feedback via behavior, precluding direct interaction among the layers of competence, belief, identity and mission. The structurally adapted Onion model, illustrated in Figure 2, aligns with the coding results of related studies and elucidates the pattern of interactions arising from behavioral influences.

5. Discussion

5.1 Conclusion

Drawing upon the Onion model, this study conducted a comprehensive analysis of factors influencing teacher learning by systematically coding 67 core documents in both English and Chinese, using qualitative meta-analysis techniques. While the existing body of relevant literature was deemed sufficient, a robust scientific framework was necessary to assess the homogeneity and heterogeneity of these findings and establish more vital interconnections among studies. Our analysis revealed a quantitative structure resembling an inverted triangular shape with a three-stage ladder, highlighting disparities in research focus between Chinese and English literature, along with their potential underlying causes. Furthermore, the study examined heterogeneity among findings, predominantly categorized as opposition and complementarity, and identified the pivotal role of learning behaviors based on coded content and theoretical underpinnings for modular model reorganization. Building upon these findings, the Onion model underwent restructuring to better align with the coded results of related studies, endeavoring to articulate interaction patterns among factors influencing behaviors.

The influences on teacher learning encompass various dimensions, including environmental, behavioral, mission and other factors to a lesser extent. However, the conventional linear model, as depicted by the Onion model, no longer adequately captures the intricate dynamics resulting from numerous iterations of research. Rather, what emerges is a complex Web of interactions and cyclical influences. Consequently, due to the high complexity inherent in the learning process, teacher learning entails a nuanced journey of cognitive transformation. This transformation is propelled by intricate interactions among multiple factors, characterized by iterative and cyclical patterns. Thus, sustained and diverse learning activities are imperative for fostering profound teacher cognition and behavior shifts. In particular, the design of teacher learning activities should embrace a blend of theoretical, practical and inquiry-based approaches. This ensures educators remain invigorated and engaged by a continuous stream of diverse stimuli. Moreover, it affords them the necessary space and time to reevaluate and refine their teaching practices, gradually assimilating novel perspectives and insights into their cognitive framework. Subsequently, these insights are translated into tangible adjustments in teaching behaviors, facilitating a meaningful pedagogical practice evolution.

5.2 Research limitations

Objectively, the hierarchical structuring of human internal cognition lacks robust empirical support. There needs to be more rigorous research directly substantiating the concept of cognitive hierarchy. Conversely, an increasing number of scholars advocate for the view that human cognition is inherently intricate and holistic. They posit that the pathway of influence from environment to cognition to behavior exhibits characteristics akin to a black box at the cognitive level. The inner workings of cognition, including the potential necessity for mediation of implicit influences, remain largely uncharted territory. The disproportionate emphasis on the interplay between the external environment and internal cognition has led to limitations in observing and exploring cognitive internals. Presently, cognitive research heavily relies on subjective narratives provided by research subjects, which are susceptible to subjective biases. Moreover, the absence of objective and efficacious means for cognitive observation exacerbates this situation. Nevertheless, advancements in neuroscience, artificial intelligence, computer simulation and related technologies offer promising avenues for attaining relatively objective insights. Through simulating and analyzing human cognitive processes and mechanisms, there exists potential for acquiring more objective observations.

Due to the limitations of the literature search and keyword design, this paper may not be exhaustive in collecting all the relevant literature, and thus, there may be a minor distortion in the data enumeration section; furthermore, the inclusiveness of teachers from various subjects and school segments in this study might have resulted in overly generalized findings, potentially overlooking factors not accounted for in the established model. Future research endeavors could enhance specificity by concentrating on teachers within particular subjects and school segments, such as a distinct cohort of pre-service chemistry educators. More precise and valid models pertaining to specific domains can be developed through the meticulous and purposeful design of research methodologies tailored to the targeted group, thereby offering refined guidance for subsequent policy formulation.

Figures

Figure 1.

Onion model, cited in Korthagen (2004)

Figure 2.

Structurally adjusted Onion model

Table 1.

Detailed results of Chinese literature coding

Factor	No. of nodes	No. of nodes (de-duplicated)/saturation	Detailed table of literature coding nodes (de-duplicated)
Environment	46	36/1.28	Career pathways/online continuing education courses/platform attraction/social identity/school climate and institutional rules/environmental difficulties/learning contexts/evaluation and feedback on teachers’ work/instructional leadership of the headmaster/critical events/school support and family support/innovative mechanisms/knowledge tacitness/knowledge complexity/school environment/teaching and learning demonstrations/TVT (thinking visualization techniques) tools/rotational exchanges/place transformation of undergraduate colleges and universities/group composition/support guarantees – group cooperation/supportive environment provided by the state/significant others/online learning communities/project communities of practice/information resources/external stimuli and support/effectiveness of classroom teaching and learning/type of school and its region/STEM education philosophy/community factors/supportive situations/learning culture/teachers’ heavy workloads/menial workloads
Behavior	10	10/1	Decision-making participation and habits of practice/time and ways of engaging in professional development/teaching philosophies and styles/teaching materials development practices/reflective processes and reflective materials/personal virtuous interactions/teacher cooperation/pedagogical practices/habits of learning/teaching by experience and convention
Competencies	11	9/1.22	Career development outcomes/absorptive capacity/knowledge structure/work engagement/ability to delay career fulfillment/age and teaching factors/educational factors/title/lack of deep reflection on experience and practice
Beliefs	10	8/1.25	Affective and developmental awareness/self-beliefs and confidence/teachers’ needs/educational efficacy/reflective purpose/attitudes/performance expectations/ease of use expectations
Identity	2	2/1	Professional identity/teacher awareness
Mission	4	4/1	Educational sentiment/self-actualization/beginning of teaching/concepts
The rest	5	5/1	Non-intellectual factors/marriage/monthly income/job factor/establishment factor

Source: Authors’ creation

Table 2.

Detailed results of English literature coding

Factor	No. of nodes	No. of nodes (de-duplicated)/saturation	Detailed table of literature coding nodes (de-duplicated)
Environment	63	40/1.58	Socio-cultural/type of training center/pressure and responsibility to take on teaching/developmental support provided by schools/curriculum accreditation standards bodies/teacher education systems/teacher management systems/teacher evaluation mechanisms/teacher professional development theories and organizations/teachers’ cultural and societal values/resource and policy support/prescribed standards of assessment of students and teachers' perceptions of them/teachers’ home institutions/institutional size and leadership/teacher team formation/mutual understanding between teachers and students/assessment and feedback/opportunities for practice/training program design/skills incentives/corporate support/empowerment through early socialization/experiential workplace learning/disciplinary and institutional differences/effectiveness of professional development programs/key features of TPD/online communities and e-learning/occupational pressures/job characteristics/school culture/colleague support/and policy and community requirements/researcher coordination and headmaster support/colleague and leader support/school climate for innovation/teaching and learning mission and goals/resources and facilities/types of teacher communities/roles and influences of those involved in the community
Behavior	18	15/1.2	Learning methods/teaching methods/developing cognitive gains/continuous learning cycle/work engagement/teaching experience/teacher team selection issues/observation/possible barriers to preconceptions/perceived behavioral control/behavioral intentions and self-reported behaviors/pedagogical behaviors/teacher’s self-reflection/teachers’ creative behaviors/technology anxiety
Competencies	21	12/1.75	Acquisition of knowledge and skills in teaching and learning/critical reflective practice/teacher leadership/pedagogical autonomy/knowledge of content/teacher’s background and experience/ICT training or not/academic qualifications/length of teaching experience/title/type of course/knowledge and understanding of professional development
Beliefs	32	19/1.68	Decision capital/perception change/attitudes and confidence in technology/self-efficacy/performance expectations/effort expectations/teaching self-efficacy/technical skills and technology self-efficacy beliefs/teacher beliefs/self-confidence/perceived ease of use/perceived usefulness/internal dialogue between intrinsic values and external influences/outlooks toward the future/attributions to problems/teacher resilience/attitudes toward learning/learning goals
Identity	5	5/1	Attitudes/personal/trust/identity/subjective norms toward the role of the family doctor and learning and teaching
Mission	5	3/1.66	Interest/teacher’s view of education/teacher’s motivation to learn
The rest	8	4/2	Age/teacher characteristics/sex/subject

Source: Authors’ creation

Table 3.

Research methods and saturation in Chinese and English literature

Types of literature	No. of qualitative studies	No. of quantitative studies	No. of mixed studies	No. of reviews	Average saturation	Total no. of documents
Chinese literature	12	8	2	5	1.1	27
English literature	16	13	3	8	1.55	40

Source: Authors’ creation