Re-imagining transformative professional learning for critical teacher professionalism: a conceptual review

ABSTRACT Transformative professional learning is connected to educational and social transformation and possibilities for critical forms of teacher professionalism. Examining and fostering this connection requires greater conceptual clarity about these constructs and how they are enacted. A conceptual review, combining narrative and systematic methods, was undertaken of research on transformative professional learning that embraced educational and social change, and of accounts of professional learning associated with critical forms of professionalism: activist, transformative, and democratic. A common analytical framework was used consisting of modes of professional learning, educational purpose, knowledge, sociality, agency, and material and systemic arrangements. The conceptual framework used in this review has wider potential for analysing professional learning and its outcomes. The review indicates that transformative professional learning is under-theorised with accounts emphasising only one or two features, usually agency, collaboration, or educational purpose. We argue that transformative professional learning should be grounded, additionally, in clarity about purpose, knowledge, and the relationship to knowledge that is developed. Different possibilities for enacting professional learning are identified that can foster critical teacher professionalism, including those rooted in teacher activism connected to wider social movements.


Introduction
Professional learning for educational and social transformation is often linked to possibilities for reimagining teacher professionalism (Kennedy 2005, p. 2014, Mockler 2005, Sachs 2016). Mockler (2005) argues for transformative professional learning and Kennedy's (2005Kennedy's ( , 2014 framework of continuing professional development provides a characterisation of different models of professional development spanning training through to transformative forms. 'Learning' and 'development' are often used interchangeably in the literature, notwithstanding important debates about terminology around the use of these terms (see Groundwater-Smith and Mockler 2009, pp. 55-57 for discussion). Some bring the terms together to refer to professional learning and development (for example, Fullan and Hargreaves 2016). Here, we use 'professional learning' as a general means to refer to both the outcomes and process. Professional learning and professional development can be defined in relation to the outcome of activities (Darling-Hammond et al. 2017), or they can be viewed as a reflexive process (Groundwater-Smith and Mockler 2009). This latter emphasis informs our review.
Conceptualisation of transformative professional development and professional learning was initially framed in response to marketisation and deregulation in teacher education in anglophone contexts. These changes have been described and researched through concepts such as 'new professionalism' (Evetts et al. 2009, Evetts 2011 and 'managerial professionalism' (Sachs 2003). Critics of new professionalism and managerial professionalism posit alternatives of various forms including democratic professionalism (e.g. Apple 1996, Hargreaves 2000, Sachs 2001), activist professionalism (Sachs 2003), transformative professionalism (Mockler 2005), and 'community teachers' as transformers (Kretchmar and Zeichner 2016). The latter encompasses informal teacher action groups (Quinn and Carl 2015) and more formal trade union activism (Buyruk 2021). Here, we refer to these different formulations collectively as 'critical professionalism'. In general, there are many overlapping terms used for related constructs and we provide a table with meanings of key terms below.
For Mockler (2005), a central premise of transformative professional learning is supporting teaching that aims for 'the transformation of society through the contribution it makes to the formation of human beings who think critically, act ethically and seek justice throughout their lives ' (p. 733). For Kennedy, transformative professional development entails reflections by participants on issues of power to critique reforms and foster democratic professionalism. Thus, arguments for the importance of transformative professional learning are made alongside, and connected to, arguments for critical forms of professionalism (Sachs 2003, Mockler 2005.
Kennedy, Sachs and Mockler's descriptions of transformative professional learning and development are not claimed as complete or comprehensive. Furthermore, since these early uses of 'transformative' in relation to professional learning and development, others have used the term differently. Here, through a review using narrative and systematic methods, we examine transformative professional learning and its relationship to critical forms of teacher professionalism. Criteria for the identification and selection of texts included explicit linking to political purposes, including critical professionalism.
These criteria bound the scope of our paper. Elsewhere, related conceptions such as teacher change and professional growth are also used (for example, Clarke and Hollingsworth, 2002) to focus on individual rather than systemic transformation within professional learning. In relation to individual transformation, there is also an important relevant body of work using Mezirow's model of transformative learning to analyse teacher professional development (e.g. Pohland and Bova 2000). Although largely outside our scope here, we note that there are resonances between accounts of transformative learning in Mezirow's model and the importance of epistemological aspects of transformative professional learning, and we reflect on this later.
In the next two sections, we discuss critical forms of professionalism and transformation, and so further set out the boundaries of the research. Identifying types of professional learning and/or professionalism may help in understanding, researching and fostering desirable phenomena. However, typologies can oversimplify and obscure processual aspects. Moreover, consideration of types does not account well for the ways that professionalism and professional development and learning are situated inthe wider professional context of teaching or the wider social system (Evans 2011, Mockler 2013, Sachs 2016, Perry et al. 2019. Others have identified the dynamic, situated, and non-linear aspects of professional learning (see, for example, Strom and Viesca 2021), and similar arguments can be made about professionalism.
Following consideration of critical professionalism, we describe the methods used in this review. Following this, we analyse the knowledge base, characteristics of transformative professional learning, the relationship of transformative professional learning to critical professionalism, and possibilities for fostering transformative professional learning before concluding, arguing that collaborative and agentic professional is a necessary, but not always a sufficient, condition for transformative professional learning and point to the need to foster a critical relationship to knowledge and knowledge production.

Critical professionalism
We begin by exploring the literature on critical professionalism to highlight the ways in which this promotes teachers' purposes within and beyond the profession. The erosion of teachers' autonomy has happened in many countries, including England (Evetts et al. 2009, Toledo et al. 2017, Perry et al. 2019, Australia (Mockler 2005), the United States (Hargreaves andGoodson 1996, Zeichner 2010), and Canada (Hargreaves 2000, Osmond-Johnson et al. 2019. Increased governmental regulation, it is argued, leads to de-professionalisation and lower professional status (Toledo et al. 2017). Different terms are used to describe these phenomena including organisational professionalism (Evetts et al. 2009), managerial professionalism (Sachs 2003, Mockler 2005, and, in the USA, new professionalism (Zeichner 2010).
Alternative possibilities for teacher professionalism use different terms but infer related constructs. Here, we use a generic term of 'critical professionalisms' and consider three terms commonly used : democratic, activist, and transformative. Apple's (1996) democratic professionalism points to the need for teachers to establish their agency as curriculum makers, consider those who are not served well by education, and support students and communities who are often objects rather than subjects of educational policy. As Hargreaves (2000) has it, democratic post-modern professionalism entails responsibilities to the education system and beyond. More recently, democratic professionalism has been constructed as resistance to ongoing challenges to public education, a call for a movement to defend this, and advocacy for community and marginalised inclusion in educational governance and the public sphere (Anderson and Cohen 2018). Terms such as 'democratic' are also used as an alternative to the term 'occupational professionalism ' (in Sachs 2016). Similarly, in Scandinavian contexts, a concern for democratic values is intrinsic to teaching (see, for example, Larsen and Mathé 2022).

Activist and transformative professionalism
Building on concepts of democratic professionalism, Sachs argued for the need for activist professionals (Sachs 2001(Sachs , 2003 to be inclusive, collaborative, and collegial, responsive to change, and enquiry orientated. These features support professional agency, an activist orientation to engagement in policy and enactment of ethical values. In arguing for activist professionalism, Sachs contends that activist teacher professionalism is concerned with wider issues of equity and social justice (Sachs 2003b). Mockler (2005) integrates Sachs' conception with the constructs of post-modern professionalism (Hargreaves andGoodson 1996, Hargreaves 2000) to argue for transformative professionalism that places trust in teachers to work autonomously, as 'creative developers of curriculum and innovative pedagogies' with risktaking embraced by courageous leaders (Mockler 2005, p. 742). Similarly, Kretchmar and Zeichner (2016) posit the possibility of teachers as transformers.

Transformative professional learning and development
We now move to consider the relationships between critical professionalism (democratic, activist, and transformative) and transformative professional learning. Proponents of democratic and activist professionalisms identify the importance of alternative conceptions of teacher education and professional learning as both a means to foster and an outcome of critical professionalism. Mockler (2005) makes explicit the need for transformative professional learning to support transformative professionalism. Drawing on contemporaneous Australian examples, she points to the conditions and cultures needed for transformative professionalism, including: • the fostering of active trust of teachers, between teachers, and with communities • openness to risk-taking • creative development of curriculum and pedagogy to support learner agency • courageous leadership In Johnson and colleagues' extensive studies of teachers in the southern United States seeking to support English language learners in urban settings (Johnson 2011, Johnson and Fargo 2010, 2014, Johnson and Marx 2009 transformative professional learning holds similar meanings. Through collaboration and openness, teachers build trusted relationships with colleagues, students, and families/carers, connectedness with all students, a classroom community of learners and encourage students to learn collaboratively and share responsibility for others. Kennedy (2005) identified a spectrum of purposes from more transmissive to more transformative forms of professional development. 'Transmissive is thought of as a method of 'preparing teachers to implement reforms' and 'transformative' aims to support teachers 'in contributing to and shaping education policy and practice' (Kennedy 2005, p. 248). The potential for teacher agency is greatest at the transformative end of the spectrum.
The transformative model of professional development is one that 'recognises the range of different conditions required for transformative practice' (p. 246) and is composed of a combination of elements drawn from other forms. It supports teachers to ask 'critical questions of the political determinants that shape the parameters of their practice' (p. 245). In Kennedy's (2014) later refinement, she notes that this middle category of transitional recognises that some type of professional development can be lead to different outcomes. She renames this category 'malleable'. The newer model also presents the categories as 'analytical devices ' (p. 692). In this framework, the models are classified sequentially against the capacity for autonomy and agency ( Figure 1).
'Teacher agency' is also used to indicate increasing autonomy, noting that 'autonomy is only ever transformative if it is translated into agency' (p. 693).
Building on her previous formulations and those of Kennedy (2005), Sachs (2011) proposed a model of types of professional development aimed at variously retooling, remodelling, revitalising, or reimagining practice. Central to Sachs' model is the purpose of professional development: • retooling is focused on new skills for teachers • remodelling suggests changing an approach to teaching • revitalising focuses on the affective aspects of teaching • and reimagining is a more thorough change in practice along the lines of Kennedy's transformative professional development.
Two features define transformative professional learning in these conceptions. First, the centrality of agency, with Kennedy's spectrum of models or forms of professional development organised around 'increasing capacity for professional autonomy and teacher agency' (p. 693). Agency is the basis for transformative learning and such learning in turn fosters agency -'emancipating' (Sachs 2011) or 'empowering' (King 2019) teachers. Second, the importance of collaborative and inquiry forms of professional learning, with collaboration happening at multiple levels; this supports teacher activism and innovation (Johnson 2011). Thus, agency, collaboration, and inquiry are linked with, first, resisting increased technicisation of teaching and managerial professionalism, and, second, more positively seeking education and social transformation.

Transformative in professional learning and professionalism: issues and questions
The constructs of transformative professional development and learning make explicit connections between teacher learning and professionalism. Teacher professionalism and professional learning are connected in multiple ways beyond their linguistic common root word -'profession'. Theoretically, they are intertwined in the associations with professional knowledge and agency, Kennedy, Mockler and Sachs identify ways that different forms of teacher professionalism accommodate or align with different modes of professional learning, and the latter in turn may help to produce different forms of professionalism. Kennedy (2007) undertook an analysis of policy documents related to teacher professional development in Scotland between 1997 and 2004 and concluded that prevailing discourses of professionalism were managerial, enforced through a process of compliance with teaching standards. The push to raise pupil outcomes and the link of these outcomes to teacher professional development has meant the development of managerial views of professionalism alongside 'an increase in performative ideologies' (Kennedy 2014, p. 691). Sachs (2016) suggests that evolving circumstances in education mean that discourse about professionalism in teaching is shifting. She offers a model that synthesises aspects of professionalism and professional development. The model is based on three themes, which have an external influence on this discourse: factors shaping teacher professionalism (such as performance cultures and increased accountability), teacher professionalism as a contested site and teacher professional development as a strategy to drive change and improve practice. She argues that accountability regimes restrict opportunities, leading to controlled or compliant professionalism, whereas teachers need to engage in professional learning that is 'personally transformative' (p. 423).
In contesting discourses of professionalism, the construct of transformative professional learning itself acts as a political actor in specific educational systems. However, Mockler, Sachs and Kennedy all acknowledge their models are not comprehensive or complete. Consequently, our review aims to address the following issues. First, the need for further theoretical development and refinement. So, for example, in Kennedy's (2005Kennedy's ( , 2014 spectrum model, different types of constructs are arranged as a continuum of discrete categories but these may not be mutually exclusive. To illustrate, 'award bearing' and 'community of practice' models are described as distinct, but collaborative enquiry and research can lead to academic awards. Similarly, in linking forms of professional learning to different types of professional development, Sachs' (2016) typology uses different categories or features in various ways across four models.
Secondly, a further need is to more fully theorise transformative professional learning across a range of aspects that are important for both understanding professionalism and professional learning. Some of these are explicit in formulations of transformative professional learning, notably teacher autonomy and agency. Others, however, tend to be implicit -such as the material and systemic relationships, organisation, and resources that can support transformational learning. Examples of organisational forms discussed in the review include school-university partnerships and teacher activist groups. As we note below, sociomaterial resources -the artefacts and materials that foster or arise in transformative professional learning -are largely absent from accounts. Others are somewhat ill-defined or not fully specified, such as the nature of educational transformation that might flow from such learning and practice.
A third theoretical issue flows from incomplete accounts in the models. This is understanding the differences and similarities with other constructs of professional learning and teacher education that share an intent for educational and political change. Democratic and activist concerns find expression through social justice teacher education in the USA and elsewhere (Boylan and Woolsey 2015) and culturally responsive teaching (e.g. Johnson et al. 2016). A more fully developed account of transformative professional learning may support exploring relationships with other critically orientated practices in teaching. To do so fully would be beyond the scope of this paper, however, our review offers a basis for future research in this area.
A fourth issue is empirical. Early descriptions of transformative professional learning provide few accounts of its enactment in practice and so provide relatively little specific guidance about how to enact transformative professional learning in other contexts. The fifth issue of concern is that because transformative professional learning is not fully specified, it leaves the term open to use in many ways. 'Transformative' is a term that has a general meaning. In scoping the review, it became apparent that in most uses in relation to professional learning, 'transformative' was used adjectively to refer to a quality or degree of professional learning separate from concerns with political intent or critical professionalism.
These concerns inform the questions that guide our review: • what is the knowledge base for understanding transformative professional learning as related to critical professionalism and how could it be improved? • what are the characteristics of transformative professional learning and development where this is linked explicitly to educational and social change and how could its theorisation be refined to support greater clarity of its purpose or outcomes? • what are the connections between transformative and other forms of professional learning and critical professionalism? • what insights follow for how transformative professional learning and critical professionalism can be fostered?

The review approach
Our review is focused on the use of the term 'transformative' related to educational and social change rather than comprehensive review of all educational research using the term 'transformative professional learning'. We combined narrative and systematic review methods. A flow diagram that provides key aspects of the process is provided in Figure 2.

Identification and screening of texts
Initially, a group of 11 texts were identified as part of a wider programme of research around professionalism and professional learning. This included 'ancestral' texts that informed conceptualisations of transformative professional learning (Kennedy 2005, 2014, Mockler 2005 and critical professionalism (Sachs 2003(Sachs , 2011(Sachs , 2016, as well as related forms of professionalism (Hargreaves 2000), and examples of teacher activism linked to professional learning (Quinn and Carl 2015, Kretchmar andZeichner 2016, Buyruk 2021). These texts informed the boundaries of the review by clarifying and narrowing the meaning of transformative and informed the search terms. We excluded papers where 'transformative' was used as an adjective along the lines of 'significant' or 'considerable' without specifying the type of professional learning or its features. We found that the term 'transformational' was sometimes used in a similar way. As a side note, there are also other uses of transformation that theorise this as a construction and identify indicators of transformation (for example, Netolicky 2019) but here transformation is largely one of the individual and organisational change rather than systemic change. These too were not included. Systematic review methods were informed by PRISMA recommendations for transparent reporting (PRISMA n.d.). Two databases were used: Scopus and ERIC. The use of two databases for the systematic element of the review and not undertaking a full search of chapters, theses, reports, and other grey literature means that the corpus reviewed is limited. However, as stated above, our aim was to interrogate the construct of transformative professional learning and its relation to potentially related forms of professionalism and from this to contribute to a theorisation of 'transformative'. The approach taken identified enough texts for this endeavour.
In both databases, two sets of searches were undertaken, focused on the period for 2000-2022. One focused on texts describing transformative professional learning and the second focused on texts describing critical forms of professionalism and professional learning related to this or developing this. Search terms and procedures varied across the two databases due to different syntax requirements, but for both database titles, abstracts and keywords were searched. Table 1 provides search terms.
Because Scopus is a generic social science database rather than education specific, an initial screening process by reading abstracts, and, if needed, full papers, screened out texts that were not related to school teaching. For example, those on medical education. Similarly, texts were rejected where 'transformative' was used adjectivally to describe a general quality of professional learning rather than having a socio-political intent. Of the 33 texts originally identified from Scopus, 24 were selected. Similarly, in searches related to critical professionalism, texts were screened out, if, for example, 'democratic' was used in passing (e.g. 'democratic society') rather than related to a form of professionalism. Of the 113 texts originally identified in relation to professionalism, 44 were selected for initial review. Due to the education-specific focus of the ERIC database and specific filters for professional development, all texts identified were selected for screening. Duplicates were removed at each step in the selection process, and then all selected texts were read using an iterative and comparative process to identify 38 texts for analysis. Following analysis, seven more texts were Educational purpose and ethical orientation Sociality -including relationship between teachers, relationship to community, relationship to learners Agency Knowledge processes and intended outcomes Material and systemic arrangements -resources, organisational structures etc excluded from the review. Exclusion at this stage was because the text did not provide any substantial material related to the research questions and the analytical framework, or there was no explicit or implicit definition of transformative professional learning/development connected to concerns for educational and social change.

Analysis
The analytical framework (see Table 2) combined contextual and descriptive codes about the text, place of origin, methodology, relationship forms of critical professionalism, and the type of professional learning described or advocated. Analytical codes for features of professional learning were developed by considering: (1) traditional constructs of professionalism emphasising the importance of professional autonomy and specialised knowledge (see Perry et al. 2019) (2) analytical models of teacher professionalism -notably Evans (2008Evans ( , 2011 and of professional learning and development (Boylan et al. 2018) (3) scoping reviews of professionalism and professional learning, including the sources that informed the search strategy and terms.
We recorded analysis of texts in a database using the analytical frame and additional emergent themes.

The knowledge base
In this section, we reflect on the knowledge base for understanding transformative professional learning as related to critical professionalism and we organise this into two parts: the corpus and type and origin of studies. Table 3 presents the corpus of 31 texts organised chronologically. Full references for the research outputs are provided in the reference list where they are starred. The tables in this section provide the in-text reference.

Type of study and origins
Type of study Texts were classified by this type of study: 17 texts were based on empirical studies, eight were conceptual, and six classified as hybrid in that they drew on empirical studies reported elsewhere. Table 4 summarises the place of origin of texts, arranged in order of frequency. As shown in Table 4, three countries have been the sites for the generation of three-quarters of the outputs. Except for Scotland and Ireland, it is notable that other European countries and educational systems are absent, as are Asian systems.

Origins of studies
The reviewed texts were a relatively small corpus with limited variation in methodology. Most studies were either small case studies or reflections on implementation rather than evaluation. A further limitation is that the corpus is skewed towards anglophone education systems. However, the review does draw on the literature from a wide geographical range and contributions including Turkey, Brazil, and South Africa, which provide important counterpoints to the anglophone examples.

Characteristics of transformative professional learning
In the introduction to this paper, we noted our caution about the use of typologies and linear models to conceptualise either professional learning or professionalism given their dynamic, situated, and complex nature. Moreover, in this study, as an added layer of complexity, professional learning took place in contexts that were not generally supportive of the political intent. As an example, the Brazilian women educators generated some of their professional learning opportunities whilst living under authoritarian rule (Jennings and Da Matta 2009 (Morrison 2018) -rather than the form itself. Thus, we discuss the characteristics of transformative professional learning in relation to each of the themes of modes, purpose, agency, sociality, knowledge, and systemic and material arrangements.

Modes of professional learning
Modes of professional learning clustered around three types: (1) collaborative enquiry and practitioner research projects (2) training and/or workshops in practice and implementation supported by follow-up workshops for expert and peer support. (3) peer groups focused on discussion, personal and professional enquiry, and action for change The third type was often connected to activist social movements with a social justice orientation (see 'systemic and material arrangements' below). Providing a frequency for each mode is not appropriate given that the review outputs were of different types -empirical, conceptual, and hybrid. Furthermore, some sources describe multiple instances or forms of professional learning and multiple sources refered to the same examples and instances.

Purpose
The purpose of transformative professional learning, like social justice concerns in education more generally (Boylan 2017), can be framed in more or less critical ways. More conservative formulations focus on learning opportunities and outcomes for those who experience injustice in education. Although not included in the current review, accounts of professional learning that use 'transformative' as a general adjective, but also have a concern for social justice, would share this orientation. Where transformative professional learning is linked to constructs such as activist and democratic professionalism a more socially liberal conception is found with an orientation that educational structures and practices need transforming (Chubbuck 2010). Going further, in those descriptions of professional learning pointing to the need to transform social structures beyond school, teaching is posited as a counter-hegemonic practice seeking to change students and society (Kumashiro 2000, Gorski 2009, Boylan 2017).
In the reviewed texts, the educational purpose and ethical orientation is generally not made explicit. Even when it is -for example, where reference is made to social justice -what this means is not described, a common issue in teacher education research concerned with social justice (Boylan and Woolsey 2015). In some outputs, an important ethical purpose is enhancing teacher agency and teacher growth (Charteris and Smardon 2015, Jones and Charteris 2017, King and Holland 2022. Where the purpose is centred on the teacher, a concern for teacher agency extends to developing activist professionals (Sachs 2011(Sachs , 2016 and teacher leadership for change (Johnson and Marx 2009). This connects to addressing disadvantage within and through education. Notable here is professional learning for culturally responsive teaching (Johnson and Marx 2009, Johnson and Fargo 2010, 2014, Kose and Lim 2010, Johnson 2011, Johnson et al. 2016, Fullam 2017) and inclusive practices (Mogliacci et al. 2016, Brennan and King 2022, King and Holland 2022.
A continuum of purposes are found where professional learning seeks change in education systems and society more generally. These are concerns for political and democratic engagements (for example, Sachs 2003, Mockler 2005, Kennedy 2014, and cultivating an ethic of resistance (Nolan and Guo 2020). Anderson and Cohen's (2018) articulation of a new democratic professionalism focuses on defending public education in the USA, reflecting ongoing structural changes and political contestation. Beyond these, arguably more radical conceptions appear in conceptions of ecojustice (Morrison 2018) and activist teachers and through trade unions and social movements (Quinn and Carl 2015, Osmond-Johnson et al. 2019, Buyruk 2021.

Agency
Teacher professional agency is often not clearly defined in the corpus. Exceptions include Quinn and Carl (2015) who understand it as the power of teachers, individually and collectively, to direct their own working lives. Jones and Charteris (2017) draw on Boylan's (2010) ecological conception of teacher agency, focussing on how agency can be co-produced through critical reflection. For Sachs (2011), teacher agency is supported by a metaphor of CPD as 're-imagining', enabling teachers to 'have some agency in identifying priorities and needs for their own professional learning' (p. 156). There is some evidence of a shift away from conceptualisations of agency as individuals towards a focus on collective (Johnson andMarx 2009, Anderson andCohen 2018) and collegial agencies (Quinn and Carl 2015). Jennings and Da Matta's (2009) study, arising from liberatory social movements, explores counter-pedagogies in the Brazilian context, highlighting possibilities for change. Groundwater-Smith and Mockler's (2009) approach to teacher inquiry resembles 'agentic teacher enquiry' rooted in the visions of Stenhouse and Elliot's action research models. Other forms of practitioner enquiry feature elsewhere, with agencies perhaps limited to an extent, for example by externally facilitated professional learning (Nolan and Guo 2019).

Sociality
Relationship building is an important feature of the papers reviewed. Several highlight the development of trusting relationships with other teachers (Mockler 2005, 2013, Johnson and Marx 2009, Sangster et al. 2013. These relationships develop and are sustained over time (Brennan and King 2022), often through models of professional learning designed to support collaboration Smardon 2015, King andHolland 2022). In one study, transformative professional development 'enabled teachers [. . .] to build supportive relationships, learn about and practice effective instructional strategies in safe environments' in addition to learning how to support students' learning (Johnson and Fargo 2010, p. 24).
Building relationships with stakeholders is a necessary feature of transformative professional learning. For Sachs, it is 'political work, it requires building collaborative partnerships between various stakeholders whose task is to work together, combining their experience, expertise, and resources' (Sachs 2016, p. 421). The narratives of women educators in Brazil emphasise collaboration and community as a means of challenging existing practices: 'regularly scheduled forums provided a space for faculty, students, and community members to critique and reconstruct pedagogical philosophies and practices' (Jennings and Da Matta 2009, p. 216).

Knowledge
Given that learning is entangled with knowing, there is surprisingly less discussion of the knowledge that is important in transformative professional learning. Some earlier texts from Australia contest discourses of evidence-based practice by emphasising the importance of enquiry-based knowledge rooted in practice (Groundwater-Smith and Mockler 2009). Some seek to harness more traditional epistemic practices in teaching such as personal critical reflection (Mogliacci et al. 2016, Jones and Charteris 2017, Nolan and Guo 2019, Brennan and King 2022, King and Holland 2022. Similarly, those modes of professional learning focused on workshops with external expertise, for example, in culturally responsive teaching, harness external authority although with more critical intent (for example, Johnson 2011, Sangster et al. 2013, Fullam 2017. Aligning with enquiry and collaborative modes of learning, others emphasise the importance of participatory knowledge rooted in teachers' collective endeavour (Quinn andCarl 2015, Morrison 2018). Mayes et al. (2021) extend the collective to include students' role in contributing to participative knowledge through student voice and others, advocating democratic professionalism and pointing to the importance of communities in knowledge creation (Kretchmar andZeichner 2016, Anderson andCohen 2018).
A weakness in the corpus is the lack of consideration of the type of epistemic orientation that transformative professional learning seeks to develop. One theme that indicates ways such a consideration could be developed is found in Kennedy (2014) who argued that teachers need to think critically about knowledge itself. One exception to this absence is the application of Belenky et al.'s (1986) feminist epistemic model of ways of knowing (Jennings and Da Matta 2009). This echoes a previous conception of 'teachers working' for emancipatory change (Povey 1997) where a critical perspective on knowledge and knowledge production was linked to what, in Sach's terms, would be an activist orientation and critical professionalism. In the introduction, we note the limits of our review related to change and teacher change as concepts and models of transformative learning focused on individual changes such as Mezirow's transformative learning model. However, in these epistemological concerns, the concept of disorienting dilemmas (Mezirow 2009) is pertinent. A disorienting dilemma is one which can cause our epistemological framework to be disrupted.

Material and systemic arrangements
Engagement in professional learning described in the corpus is broadly located within one of the structural arrangements shown in Table 5.
Many emphasise partnership and collaboration as important features. Some are clearly part of larger, funded studies, for example Mayes et al.'s (2021) study is funded by the Victorian Department of Education, related to the long-running Teach the Teacher programme. Several studies focus on university researchers evaluating small-scale practice initiatives (e.g. Jones and Charteris 2017, King and Holland 2022).
Morrison's study is an example of activist-based transformative professional learning, exploring experiences of participants in a Critical Friends Group, 'a professional development model dedicated to improving teachers' practice through cooperative, reciprocal learning' (Morrison 2018, p. 111). Quinn and Carl's (2015) study of a Teacher Action Group, a community-based group of around 100 members/volunteers, focussed on school transformation.

The relationship of transformative professional learning to critical professionalism
Above, when descriptions of critical professionalism were reviewed, we noted that the boundaries and distinctions between democratic, activist, and transformational professionalism were blurred. This is also the case when considering transformative professional learning. At the risk of reifying differences in transformative professional learning as types, there are three broad clusters of examples reported in the studies in the corpus. These are shown in Table 6.
In one set of texts, discourse of professionalism was more prominent with reference to activist, transformative or democratic professionals or professionalism. However, there was not a clear distinction between these three different terms. Across this set, teacher collaboration, enquiry and agency were common as means to develop such professional orientations. A second group of texts, predominantly from the USA, were concerned broadly with social justice as a professional orientation with a specific focus on culturally responsive teaching. The third group were those, identified in the section above on material and systemic arrangements, where professional learning was rooted in, and supported by, engagement in social movements and teacher activist networks and organisations. This points to a different type of activist orientation than that posited by Sachs and others. Sachs' concept of the activist professional reclaims, and then extends, more traditional concepts of occupational professionalism. In comparison, the social justice teacher's activist orientation suggests other possibilities for re-imagining teacher professionalism. Funder/instigator/organisation Details Local/regional authority/school district Local/regional authority/school district supported initiatives with a small number of schools Universities University researchers working in research collaborations with smaller number of teachers University school partnerships Informal/outside education system Formal trade union professional learning More informal social movement and activist based transformative professional learning Table 6. Clusters of orientations to critical professionalism. Informed by this review, we turn to considering possibilities for fostering transformative professional learning. Above, we identified three systemic and material arrangements found in the examples of transformative professional learning. Each of these three types of arrangements may provide models for those seeking to foster transformative professional learning, with selection and programme development made depending on local contexts. However, for such approaches to move beyond pilot, small-scale and local initiatives, there is a need to connect such initiatives. This could be around shared professional learning foci or common system arrangements -such as teacher action groups. In this review, we identified several initiatives rooted in and informed by external activist networks, including social movements. Drawing on social movement theory more widely, specific examples of transformative professional learning could be linked and connected to develop a movement for transformative teaching learning at its heart. This re-invigorates Sachs' description of activist professionalism, but rather than university-school partnerships as the nexus, it points to structures and networks that are outside formal educational structures. Such networks need not be limited geographically, particularly when based on modes of critical enquiry groups (such as that reported by Morrison 2018).

Conclusion
Focusing on texts using 'transformative' with a political intent and on descriptions of professional learning connected to critical professionalism, our review addressed four questions. These focused on the knowledge base related to transformative professional learning and critical professionalisms, the characteristics of transformative professional learning as described and how it could be better theorised to support greater clarity of its purpose or outcomes in its relationship to critical professionalism, and ways transformative professional learning could be enacted to support critical professionalism.
This review shows that the knowledge base on transformative professional learning as related to critical professionalism is limited in terms of the volume of the research and its geographical location. Empirical studies tend to focus on relatively small number of teachers. This likely reflects prevailing educational contexts hostile to emancipatory intent and critical professionalism. There is the need to develop and research programmes at a greater scale.
Transformative professional learning and development occur with considerable variety and can be enacted in different ways. Three modes of professional learning were identified: collaborative inquiry and practitioner research, training, or workshops led by experts and peer groups, and these were supported by various forms of material and systemic arrangements. However, these modes are generic forms of professional learning and do not distinguish transformative instances. Rather than a set of types, transformative professional learning has characteristics in relation to: • purpose -for educational social and political transformation • agency -to suppose activist professionalism • sociality -collaborative partnerships • knowledge -criticality about knowledge and knowledge production Although beyond the scope of this review, these four aspects of professional learning are potentially useful in designing and researching professional learning in general.
Transformative professional learning connects to three different critical professional orientations. The most frequent in the reviewed papers was described variously as activist, democratic, or transformative professionalism. The second we referred to as fostering social justice teachers. As we noted, there is a considerable body of research on teaching for social justice and there is potential to enrich that research by consideration of professionalism and transformative professional learning. The third form we have referred to as social movement teacher activists. Social movements may be informal or more formalised movements, such as trade unions. The key here is the connection to external activist networks.
This third orientation has considerable potential for fostering transformative professional and critical professionalism.
A significant limitation of the review is the extent of the knowledge base. Many issues not addressed are relevant to transformative learning, including the importance of emotionality and identity (Boylan and Woolsey 2015). Borko (2004) proposed a scale for forms of research on teacher professional development that had three levels: studying programmes on a single site; studying a single programme enacted at more than one site; or comparing different programmes at different sites. In terms of the empirical basis for considering the relationship between professional learning and critical professionalism, the knowledge base is drawn from studies at the first level. An exception to this is the body of work by Sachs, Mockler and Groundwater-Smith, considering different programmes in Australia. However, here the study is retrospective in developing models of transformative learning rather than using such models to develop programmes. Johnson (with others) undertook a notably sustained programme of research on a model of transformative professional development. However, the number of school sites and teachers involved is limited.
As noted earlier, the methods used to identify texts meant that related literature, particularly empirical research, was not included in social justice teacher education and culturally responsive teaching, unless it was linked to professionalism. If the analytical model of transformative professional learning was now applied to extend the search, a larger knowledge base could be identified. This constraint may be addressed in the future through the broadening of the definition of transformative professional learning to include, for example, social justice teacher education. Nevertheless, although more extensive in terms of the volume of outputs, research on social justice teacher education also generally does not take place in forms where programmes are implemented on multiple sites (Boylan 2017). In developing this knowledge base, there is a need for greater clarity of terms.
A common recurring feature across different instances of transformative professional learning is the importance of agency and of collaborative sociality. Reflecting more or less critical approaches, the nature of this agency and collaboration varies from more collegial forms consistent with traditional occupational professionalism and more collective social relations and so collective agency.
We suggest that collaborative and agentic forms of professional development may be a necessary condition for criticality, arguably a key component of transformative professional learning, but they are not sufficient. A deliberate emphasis on teacher agency, through active engagement and selfdirection, does not necessarily lead to criticality. This points to the need to give a fuller and more detailed account of transformative professional learning beyond teacher agency and collaboration. In accounts of transformative professional learning, there is less discussion of knowledge and the relationship to knowledge that is developed.
Our analysis contributes to distinguishing between forms of professional development and learning that are badged as transformative but that may serve narrower educational purposes, promoting reproductive and culturally conservative views of knowledge; at best performative collegiality or worse, competitive entrepreneurship; restricted and individualised teacher agency; and hierarchical material and system arrangements. This informs possibilities for enacting transformative professional learning to foster critical professionalism.