Teacher and Middle Leader Research: Considerations and Possibilities

Abstract

This essay explores research on teacher and middle leadership. It begins by considering the definitions and the conceptual overlap between teacher and middle leaders and briefly considers the volume and sources of research information. Six areas in which trustworthy claims can be made about the roles are then explored: teacher and middle leader definitions, impact, interventions, leadership focus, identification, and supports/hindrances. The essay concludes by considering policy recommendations, practice recommendations and future research directions.

1. Introduction

Whilst principals have been the focus of much of the educational leadership research, with changes to school structures and expectations over the last 60 years and changes in societal expectations, such as the widespread adoption of school-based management, the rise of managerialism and more egalitarian workplaces [1], there has been a concern over the last thirty years to explore the leadership work of others in schools. Much of this research effort has been through exploring distributed views of leadership, with these views typically focused on the interaction between people in workplaces rather than on positional leadership. However, there have also been parallel research streams exploring the leadership work of others in schools in formal and informal leadership roles through the considerable literature on middle leaders and teacher leaders.

With the now considerable research on teacher leadership [2,3,4,5,6,7], a problem is that much of this work overlaps with research on middle leaders [8,9,10,11,12,13,14] because of the conceptual opaqueness in defining teacher leadership and middle leadership. Indeed, in a review on middle leaders, De Nobile [9] suggested that the terms middle leadership and teacher leadership were becoming interchangeable.

This essay helps to understand better the contribution of middle and teacher leadership research to leading schools. It begins with a substantial section exploring how middle and teacher leadership has been defined and modelled before briefly considering the sources of research. For the rest of the paper, trustworthy claims from the research are explored, including impact, interventions, leadership focus, identification, support, and hinderances. Policy implications and future research directions conclude the paper. Hopefully, the essay helps the reader to understand the rich corpus of research on teacher and middle leadership, encourages practice and policy changes to support these leaders better, and stimulates further research. For this special issue in Education Sciences, it may help locate the importance of the other articles in the wider corpus of research.

2. Defining Middle and Teacher Leadership

2.1. Definitions

There is considerable richness in how middle and teacher leaders have been defined and considerable overlap and differing views. From a research point of view, this is problematic because it is often the case that it is unclear as to the phenomenon research is reporting on, especially in much of the teacher leadership literature.

In trying to define the work of middle and teacher leaders, context is important, as Hallinger [15] has articulated for leadership in schools, and the International Study of Teacher Leadership has shown for understanding teacher leadership across country contexts [16,17,18]. For example, in small schools that have a teaching principal and a small number of teachers, there is not really a need for a conception of teacher or middle leadership as all staff need to be involved in leading and managing the schools [19,20]. As another example, in low GDP countries, basic resource issues mean that there are more pressing concerns like clean water, stable electricity supply and adequate furniture before more complex leadership structures can be considered [21]. Further discussion of context is included at the end of this section. However, for now, the following definitions are presented in full acknowledgement that across the world, in many contexts, these ideas of teacher and middle leadership may not apply, and it may not even make sense to try and apply them.

2.1.1. Middle Leaders

Research about middle leaders has evolved over a quarter of a century to have a degree of definitional clarity. In a review of the area, Gurr [11] (p. 115) defines middle leaders as ‘teachers who have an additional formal organisational responsibility, with this typically having a curriculum (e.g., in charge of a learning area) or pastoral (e.g., in charge of a year level) focus.’ De Nobile [8,9] considers middle leaders to be positioned organisationally below the principal and any other senior leaders but above teachers. The key difference from teachers is that they have a defined organisational responsibility, such as a formal role (also see [14]). The key difference between principals and other senior leaders is that they retain substantial teaching responsibility. Middle leaders often have position titles such as director of teaching and learning, curriculum coordinator, subject coordinator, domain leader, professional learning team leader, head of department, student well-being coordinator, year-level coordinator and so forth. The titles depend on context, such as country/regional location, school type and school level.

However, there remains some complexity and ambiguity. Whilst these definitions tend to exclude deputy principals, or those with similar overseeing roles such as the head of a campus or school section, because of their lack of teaching focus, some researchers include them as middle leaders (e.g., [22]) and some even argue that not all of the people in these roles are leaders. For example, De Nobile and Ridden [23] suggest that an administrative-focused deputy principal is less like a leader than a middle leader with significant strategic responsibilities. Teachers are also excluded as they usually do not have a formal position of responsibility, even though some will be exerting leadership through informal means (and properly considered as teacher leaders, which is explored next). There are further confusions, such as the term ‘leading from the middle’ which can be either a system view where principals are in the middle between the system and schools (e.g., [24,25,26]) or focused on schools (e.g., [27,28,29]); and, the inclusion of nonteaching staff as middle leaders [8].

So, middle leaders in schools will typically have a formal leadership role alongside a substantial teaching role. Whilst there will always be a need for contextual consideration, this simple view conforms well to how most researchers define middle leaders.

2.1.2. Teacher Leaders

Compared to middle leaders, the literature on teacher leaders varies considerably in how it is defined. Exploring several reviews of teacher leadership provides a developmental narrative of the area. Webber and Okoko [18] described how there have been four comprehensive reviews of teacher leadership over the past two decades [4,5,6,7]. In recent times, more reviews have occurred with Pan, Wiens and Moyal [30] notable for their claim of thoroughness over a long review period (1964–2021). The definitions used in these major teacher leadership reviews are described in this section.

The work of York-Barr and Duke ([7], pp. 287–288) is regarded as a seminal paper in the field [30] and described teacher leadership as:

‘The process by which teachers, individually and collectively, influence their colleagues, principals and other members of the school communities to improve teaching and learning practices with the aim of increased student learning and achievement.’

This is an influence-focused definition, which does not distinguish between different types of teachers (those who only have teaching responsibilities, those who have teaching responsibilities plus other organisational responsibilities or those with no teaching responsibilities) or individual versus group responsibility. As such, it is a very broad definition that obviously overlaps with research on others in schools, like middle and senior leaders.

Over a decade later, there were three important reviews, with variations on how York-Barr and Duke [7] viewed teacher leadership. Wenner and Campbell ([6], p. 140) attempted to narrow the focus by defining teacher leaders as

‘…teachers who maintain K–12 classroom-based teaching responsibilities, while also taking on leadership responsibilities outside of the classroom.’

They noted that teacher leaders should be leading the whole school and not promoting a particular program/curriculum. They regarded schools as complex systems of connected actors in which teacher leaders can lead beyond individual teachers ‘to influence the entire school, community, and profession’ ([6], p. 140). Compared to York-Barr and Duke [7], not only have they defined more precisely who might be a teacher leader, but they have also expanded the scope of influence beyond the school. The definition provides a separation from middle leaders who typically have a program/curriculum responsibility that is not whole school focused. However, it does not exclude some middle leaders, such as student welfare or student leadership coordinators, who will typically have a whole school focus.

Nguyen, Harris and Ng [4] used Katzenmayer and Moller’s ([31], p. 6) definition, in which teacher leaders

‘…lead within and beyond the classroom, identify with and contribute to a community of teacher learners and leaders, and influence others towards improved educational practice; and accept responsibility for achieving the outcomes of that leadership.’

This is a broad definition that conflates good teaching with leadership and implies collaboration, direction setting and influence as leadership features. It does not provide the distinction between teacher and middle leadership as provided by Wenner and Campbell [7] and seems to privilege collaborative endeavours.

In Schott, van Roekel and Tummers’ [5] review, they used and encouraged other scholars to use the definition of York-Barr and Duke [7], which means that they also had conceptual ambiguity about including middle and other leaders in their definition.

Pan, Wiens and Moyal [30] conducted a science mapping of teacher leadership through a bibliometric review. Their intention was to uncover patterns of publication, citation, and cocitation. Unfortunately, whilst claiming to ascribe to Wenner and Campbell’s [6] definition, they did not make any attempt to define this beyond the keyword searches related to teacher leadership and teacher leaders, and with no substantial analysis of the articles included in the review, there is no real sense of how they conceived of teacher leadership.

2.2. A Statement about Context, Organisational Design and Teacher and Middle Leadership

One of the reviewers made the pertinent observation that in writing this essay, I have ignored the theoretical frameworks in which the comparisons are made and that the overarching framework is probably best described as Weberian. I agree with the reviewer, and in the next section, where I describe briefly the sources of information, it is clear that most of the research is located in countries that have constructed schools based on views of organisations that draw on Taylorism and Weberian organisational and social structure in an era of schooling described and criticised by Senge et al. [32] as the industrial age system of schooling. As an example of how school structures and teacher career paths are described in these countries, consider the following diagram shown in Figure 1, which I have developed using three Australian career frameworks: the teacher career frameworks from the two largest school systems, the New South Wales Department of Education [33] and the Victoria Department of Education [34], and a national teacher framework developed by the Australian Institute of Teaching and School Leadership [35].

Based on the definitions of middle and teacher leaders provided above, the red and grey double-ended arrows show where the definitions fit into these career frameworks. The red arrows show how middle leadership is contained within the emergent/team leadership, teacher leader/middle leaders or teachers with leadership responsibilities/leaders with teaching responsibilities categories in each career framework. Teacher leadership, however, has a wider range of possibilities and can be considered as the work of teachers before they take on a formal leadership role (short grey arrow) or overlap across middle leadership, and even extend beyond schools to a system focus (long grey arrow with the question mark on the right end). The green arrow indicates emerging interest in the leadership of beginning teachers through research focussed on the leadership demands on early career teachers (LDECT; see [36]) and first-level leadership [37].

There are, of course, other ways to structure schools, such as that evident in many Steiner/Waldorf schools that have a collectiveness notion of leadership through the key decision-making group, called the College of Teachers, which all teachers are members of [38]. But across countries, there is a level of cohesion to the industrial age model, which is both striking and perplexing, with many calls for radical changes to schooling going unheeded (e.g., [39,40]). This adherence to a bureaucratic model that can be widely and easily implemented and impacts on the work of those in schools, This is what is being considered in this paper—schools in those contexts where the structure of schooling means teacher and middle leadership roles are evident.

2.3. Conclusions

From this brief review, it seems that the area of middle leadership is more clearly defined and generally includes someone working as a teacher who has additional formal responsibility for an area of importance to the school. Teacher leadership is less certain and can range from teachers with no other formal responsibilities who are influential beyond their teaching. However, it can also include teachers with formal positions, and some views argue that the teachers should be influential across the school and even influential outside of the school context. So, teacher leadership as a concept can be small or large in scope.

3. Volume and Sources of Research Information

Research on teacher leadership has been increasing for some time [4], with Harris and Jones [41] indicating it has become the fourth major area of study after instructional, transformational and distributed leadership. After a surge of interest in the 1990s and early 2000s, middle leadership research has gained renewed interest since about 2017 [11,42]. Whilst there are some differences across the reviews about where the research is originating, there has been a consistent presence of research from the UK (especially for middle leadership) and the USA and Canada (especially for teacher leadership) over the past three decades [11,30]. There has been a consistent contribution from Australian researchers, with notable contributions for teacher leadership from Crowther and colleagues at the turn of the millennium (e.g., [43]) and a notable increase from about 2017 in research on middle leadership [8,9,10,44,45]. Also evident during the 2000s was the expansion of the knowledge base to include research from countries in Asia and the Middle East [30]. Of course, all these papers are reporting on research written in English language journals. Incorporating research published in other languages is needed, especially from Spanish and Chinese language journals.

4. Trustworthy Claims about the Work of Middle and Teacher Leaders

Gurr’s [11] review of research about middle leaders made claims across five dimensions, and these are used as the basis for this section, with references related to teacher leadership added to arrive at trustworthy statements of knowledge about middle and teacher leadership across six areas: teacher and middle leader definitions, impact, interventions, leadership focus, identification, and supports/hindrances. The claims (indicated in italics) made here are based on a variety of sources of information, including key review articles of teacher and middle leadership supplemented by consideration of pertinent examples of high-quality empirical research published in books, book chapters, theses and journal articles. I do not claim thoroughness here as the sections are very brief to fit within the constraints of the paper, but I do submit that the knowledge is based on good research, and there are sufficient references for the interested reader to pursue further reading.

Before the summaries are provided, it is worth stating a claim arising from the preceding discussion of how teacher and middle leadership are defined. This is the first claim.

• Claim 1: Teacher and middle leadership are not the same concepts, although there might be overlap depending on how they are defined. Teacher leadership is mostly about the work of teachers who exert influence on teachers and the school beyond their teaching work, and these people do not have a formal leadership or organizational role outside of their teaching. Middle leadership is mostly about teachers who also have a formal leadership or organizational role, and exert influence on teachers and the school.

4.1. Impact

• Claim 2: Teacher and middle leaders can impact significantly on students, teachers and schools.

It is important that middle and teacher leaders make a difference in their schools; otherwise, there is little point in focusing on these types of workers.

There is sufficient evidence to claim confidently that middle leaders can impact positively on students, teachers and schools [8,9,14,46,47,48,49,50] and teacher leaders [5,31,43]. De Nobile [8,9] described middle leaders as impacting teaching quality, teacher attitudes and student outcomes, whilst Lipscombe et al. [14] described the impacts as including teacher capacity, school reform, teacher motivation and morale and student learning. Importantly, the impact of middle leaders is enhanced when principals and middle leaders act together [12,45,47,48,50,51]. Conversely, when middle leaders are not supported by principals and other school leaders, their work is constrained and hampered, and their impact is reduced [12,45]. Leithwood [50] distinguished between middle leaders who evaluate and supervise teachers versus those who offer collegial support and guidance, with the former having a far greater impact on teaching and learning. Relatedly, Farchi and Tubin [52] found that successful schools tended to have middle leaders who focused more on pedagogical behaviour than administrative behaviour.

Teacher leaders are also considered an important source of leadership impact on student outcomes, with Katzenmeyer and Moller [31], in their influential book about teacher leaders, describing them as the sleeping giants in school success. Crowther and colleagues (e.g., [43,53,54]) have developed a concept of parallel leadership in which teacher leaders, middle leaders, principals, and even student leaders [55], working together, have been shown to impact a school’s improvement journey positively. Schott et al. [5] described how teacher leaders impact the student (engagement and achievement), teacher (e.g., job satisfaction, problem-solving), school (e.g., curriculum and instruction) and supra-school levels (e.g., parent involvement, policy influence). Interestingly, in their review, Wenner and Campbell ([6], p. 163) did not find any teacher leadership studies that examined the impact of teacher leaders on student learning: ‘This omission stood out within the literature, particularly because a commitment to student learning is articulated in the ways that most define teacher leadership, including how we defined it for the purposes of this research.’

As Wenner and Campbell ([6], p.162) noted, an overlooked impact is that on the teachers themselves. In terms of their teacher leadership review, they noted negative and positive impacts on teacher leaders, including stresses and difficulties in doing the work, changing relationships with peers and administration, increased positive feelings and professional growth and increased leadership capacity. Similar findings are found in the middle leadership literature, for example, Koh [56] noted the pressures and difficulties, work intensification and role change for middle leaders in Singapore, whilst Huerta Villalobos [57] noted an enhanced sense of professionalism and worth for middle leaders in Chile who were Technical Pedagogical Head.

4.2. Interventions

• Claim 3: The way middle and teacher leadership is enacted varies across contexts, but there are consistent elements that include improving teaching and learning, working collegially with colleagues and fostering collective endeavour, improving school conditions and being critically reflective about what schools do.

Once impacts are established, it is important to understand the work of middle and teacher leaders.

Gurr [11] suggested that the way middle leaders improve student outcomes is through establishing the conditions (e.g., area direction, resource acquisition and distribution, staff development, supportive culture) that lead to collective endeavour by a group of teachers to improve teaching and learning [8,10,12,44,45,47,58]. Developing staff collegiality can also have many benefits, but to have a positive influence on student outcomes, this needs a focus on improving teaching and learning [49,50].

Three examples follow that illustrate how the work of middle leaders is conceptualised in research and standards development.

From his review of the middle leader research, De Nobile [8,9] created an input/output role model that helps to clarify the work of middle leaders:

• Inputs. Middle leadership is enhanced when the following aspects are present: principal support, school/system culture, professional development, enthusiasm/drive, and knowledge of curriculum, pedagogy and assessment.
• Roles. Middle leaders can have multiple roles that can be student-focused, administrative, organisational, supervisory, staff development and strategic. These are ordered from managerial (student-focused) to leadership (strategic).
• Enactment of roles. The roles are enacted through managing relationships, leading teams, communicating effectively, managing time and managing self.
• Outputs. The work of middle leaders can impact teacher quality, teacher attitudes and student outcomes.

A survey, the Middle Leadership Roles Questionnaire—School Edition (MLRQ-SE), has been developed based on this model covering the following roles: staff development, managing students, administration, organising people, managing curriculum, staff supervision, and leading learning and change [59]. In this paper, the seven roles were confirmed by exploratory factor analysis on a sample of 2608 middle leaders in New South Wales, Australia.

Reporting on their practice-focused studies of middle leaders, Grootenboer and Edwards-Groves ([60], pp. 83–84) described areas of activity for middle leaders through three practice pairings.

• Leading—teaching: teaching and leading practices are viewed as intertwined and working together. Leadership practices are enhanced through their teaching experience but constrained by having to be in the classroom. Modelling is a core practice.
• Managing—facilitating: This is focused on ‘administrative and pragmatic practices related to professional and curriculum development’ (p. 84). Bridging and brokering are core practices.
• Collaborating—communicating: The key idea is that leadership is realized through the practices of others and the focus is on creating communicative spaces for teachers to collegially develop and share pedagogical practices. Communication is a core practice.

They summarised this as:

‘The practice of middle leading involves engaging in (simultaneous) leading-teaching by managing and facilitating educational development through collaborating and communicating to create communicative spaces open and responsive to the change needed for developing particular practices of teaching and learning in this school or that.’ ([44], p. 248)

This view is incorporated into the Middle Leading Practices in Schools Survey (MLPSS) [61]. In a study involving 199 middle leaders from four Australian states, factor analysis confirmed four factors: leading and managing school teaching, learning and curriculum; supporting teacher colleagues’ development; collaborating with teacher colleagues on teaching and learning; and collaborating with, and advocating to, the school principal [61].

In 2024, the Australian Institute of Teaching and School Leadership (AITSL) [62] published middle leader standards and these now complement the previously published teacher and principal standards. These three standards are shown in

Table 1. A continuum of increasing leadership capabilities ([62] p. 11).

Australian Professional Standards for Teachers	Professional Standards for Middle Leaders Australian	Australian Professional Standard for Principals
1. Know students and how they learn 2. Know the content and how to teach it 3. Plan for and implement effective teaching and learning 4. Create and maintain supportive and safe learning environments 5. Assess, provide feedback and report on student learning 7. Engage professionally with colleagues, parents/carers and the community	STANDARD 1 Enabling dispositions 1a. Open-mindedness 1b. Interpersonal courage 1c. Empathy 1d. Perseverance and resilience STANDARD 2 Enabling knowledge and skills 2a. Using relevant knowledge 2b. Solving complex problems 2c. Building relational trust 2d. Self-reflection STANDARD 3 Enhancing understanding and respect for Aboriginal and Torres Strait Islander Peoples 3a. Histories 3b. Communities 3c. Reconciliation 3d. Monitoring learning progress STANDARD 4 Coordinating high impact teaching and learning 4a. Curriculum 4b. Pedagogy 4c. Assessment STANDARD 5 Leading improvement in teaching practice 5a. Professional learning 5b. Evidence-informed practice 5c. Collaborative practice STANDARD 6 Managing effectively 6a. Ensuring a safe, supportive and orderly learning environment 6b. Students, parents/carers and the community 6c. Staff management 6d. Resource allocation 6e. Strategic planning 6f. Administrative systems and processes	Personal qualities, social and interpersonal skills Vision and values Knowledge and understanding Leading teaching and learning Developing self and others Leading improvement, innovation and change Leading the management of the school Engaging and working with the community

, and they provide considerable clarity for teachers and middle leaders to conceptualise their work and plan for their career progression.

In developing the standards, AITSL [62] noted that most middle leadership roles fall under three broad categories: pedagogical leadership (improving teaching and learning in one or more curriculum areas), student-based leadership (focused on student pastoral and welfare matters), and program leadership (leading a specific program).

For teacher leaders, there are many conceptions of their work, and two research and one standards view are provided here as illustrations. Teacher leaders are often focused on the development of colleagues to improve curriculum and pedagogy. They may also have social justice, change champion, critical friend and advocacy functions [43].

Muijs and Harris [63] described six key activities of teacher leaders:

• continuing to teach and improve their own individual teaching proficiency and skill
• organising and leading peer review of teaching practices
• providing curriculum development knowledge
• participating in school-level decision making
• leading in-service training and staff development activities
• engaging other teachers in collaborative action planning, reflection and research

Later, building on the observations of York-Barr and Duke [7] and incorporating research such as that of Muijs and Harris [64], Nguyen et al. [4] described the work of teacher leaders as including:

• Coordination and management
• School or district curriculum work
• Professional development of colleagues
• Participation in school change/reform/improvement
• Parent and community involvement
• Pre-service teacher education
• Action research
• Promoting social justice

In the USA, there is a history of having a standards-based approach to considering the work of teachers and school leaders. A good example is the Teacher Leadership Exploratory Consortium [65], which developed the Teacher Leader Model Standards, which included seven domains:

• Domain I: Fostering a collaborative culture to support educator development and student learning
• Domain II: Accessing and using research to improve practice and student learning
• Domain III: Promoting professional learning for continuous improvement
• Domain IV: Facilitating improvements in instruction and student learning
• Domain V: Promoting the use of assessments and data for school and district improvement
• Domain VI: Improving outreach and collaboration with families and community
• Domain VII: Advocating for student learning and the profession

These domains provide a sense of the work that teacher leaders might do. The domains are similar to the work of others (e.g., [43]) and continue to generate research interest a decade after their publication (e.g., [65]). They also mapped well to standards for leadership (Interstate School Leaders Licensure Consortium (ISLLC) Standards and teachers (Interstate Teacher Assessment and Standards Consortium (InTASC) [65].

Whilst most descriptions of teacher leadership will have a strong connection to improving teaching and learning and doing so through collaborative and collegial practices [66], this is also true of many of the roles of middle leaders. Thus, yet again, there is an overlap between the concepts.

One final area to note is the work of middle and teacher leaders beyond schools. Most of the middle leader research is centred on leaders of curriculum or pastoral areas as these are the main areas of activity. There is little research that extends to work beyond their school settings to, for example, influence several schools or a whole school system. This is not to say that middle leaders will not be involved in this work, but there is not a substantial body of research that provides clarity on this type of work. However, in thinking about this for middle and teacher leaders, some of the teacher leadership research from the USA that explores the work of teacher coaches might be helpful [6], and there are conceptions of teacher leadership that argue for the potential of influence beyond the school (e.g., [6,43,54]). There are also roles like the Technical Pedagogical Head in Chile that have the potential for wider influence [57]. However, being realistic, most teachers and middle leaders do not do this because of their role description and focus and time constraints. This work is properly the work of principals and senior leaders.

4.3. Leadership Focus

• Claim 4: Middle and teacher leaders can have a leadership focus when there are high expectations and role clarity in regard to this work.

Since the arrival of instructional leadership as an important part of effective schools, there has been a push to focus on leadership in addition to management [67]. There are aspects that help middle and teacher leaders to be leaders as well as managers.

It has long been acknowledged that both management and leadership skills are important for school effectiveness and improvement [67]. Teacher and middle leaders can be supported to have a leadership focus rather than a managerial or administrative focus. High expectations and role clarity help in this regard [45,52,54]. High expectations come from both the middle and teacher leaders themselves in terms of their sense of agency [68] and from principals and senior leaders about what they want from the roles [12]. Role clarity serves to give balance to the leadership and management functions that middle leaders typically have [52,69]. Lipscombe et al. [14] described how prioritising leadership over management for middle leaders was possible when the following conditions were evident: an ethical school culture founded on respect and trust; autonomy and respect for teachers’ professionalism; and principal and school executive conditions which support leading, including giving middle leaders the necessary time, space and legitimate authority. Having leadership expectations of the roles that are shared by middle leaders and principals (and other senior leaders) and operating in a supportive environment is especially important if middle leaders are to impact positively on teaching and learning (e.g., [47,48,51,70,71,72]).

4.4. Identification

• Claim 5: Leadership preparation needs to begin in initial teacher training, and then leadership skills, qualities and dispositions need to be developed and supported through teacher, middle and senior leadership phases.

Recruitment and professional development are important both in terms of the quantity and quality of middle leaders [12,73,74] and for teacher leaders, there is concern about beginning leadership development in initial teacher training [75,76] and then continuing this development as careers progress [36,64]. To ensure there are sufficient teachers who have the skills and characteristics to be successful middle and teacher leaders, there is a need to encourage teacher aspirations, have appropriate selection, induction and support processes (such as mentoring), and ensure there is ongoing review and development [12,64,74,77,78,79,80].

4.5. Supports and Hindrances

• Claim 6: Teacher and middle leadership work can be supported through developing leadership expectations in teachers, providing leadership preparation and development programs, ensuring work roles are well defined, having both leadership and management expectations, having a supportive school culture and structure, and having the support of the principal and other senior leaders. The absence of these diminishes the work of teachers and middle leaders.

Considering the teacher and middle leader research reviewed in this paper and research on middle leaders over a twenty-year period [12,45], there are at least five practices that help support the work of teacher and middle leaders. This includes a well-defined role with both management and leadership expectations, a disposition to be proactive in their own professional development, the active support of the principal and other school leaders, access to appropriate leadership development programs and an overall supportive school culture and structure (e.g., sufficient time release to do the work).

These areas are supported by the review of Lipscombe et al. [14], who indicated that middle leaders need leadership development opportunities (such as induction/mentoring/coaching, appraisal and leadership courses) and that they need support from the principal, clear role descriptions, and to work in a distributed leadership and supportive school culture with trusting collegial relationships. It also supports the teacher leadership view of Schott et al. [5] in terms of the antecedents they identified (personal skills, preparation and personality; principal support; peer support; supportive work environment; system training, certification and networks) and that of Wenner and Campbell [6] in terms of typical preparation pathways including local training, professional learning and, in the USA in particular, formal postgraduate programs. Muijs and Harris [63] noted that teacher leaders needed time for professional learning, collaborative work and opportunities for continuous professional learning. In summarising the work of the International Study of Teacher Leadership (ISTL), Webber [81] noted that support for teacher leaders included organisational readiness (e.g., shared decision-making, principal support, teamwork, staff stability), system support (e.g., shared/distributed leadership, principal support) and having a professional learning community (e.g., staff collegiality, common purpose). Finally, in terms of providing professional learning and capacity-building support, Bryant and Walker [73] describe three ways to support middle leader development through school-based professional learning programs. Without going into the details of these programs, the point of mentioning this study of 12 schools in four East Asian societies is to highlight how there are many ways to provide this type of support and the necessity of providing contextually relevant programs.

There are factors that diminish the effectiveness of middle leaders, with these being the negatives of many of the factors noted above. These factors include a lack of understanding and organisational support by senior leaders, lack of professional preparation and leadership development, underdeveloped professional knowledge and capability, a focus on administrative practices, ostracisation by colleagues, lack of shared school values, lack of status and formal authority for teacher leaders, lack of shared decision making and the work of teacher unions and systems [6,12,63,68]. In summarising the work of the ISTL, Webber [81] noted several areas that constrained the work of teacher leaders, including principal unfamiliarity with teacher leadership, legacies of autocratic leadership and low levels of professional identity.

5. Conclusions—Policy Implications, Practice Recommendations and Future Research Directions

5.1. Introduction

This paper has described how middle leadership research tends to focus on those in schools who have a substantial teaching load and an additional organisational role. In contrast, teacher leadership has a variety of definitions, from teachers with no other role who are influential beyond their classroom through to those who have formal organisational roles and who may be influential within and beyond their schools. With the more expansive definitions, teacher leadership often overlaps with middle leadership and, sometimes, senior leadership. So, a problem in interpreting the research is to understand clearly what the researchers are reporting on. A solution is simply to ensure both sets of research evidence are used to conceptualise and support the leadership work of teachers who are not in senior leadership roles in schools—schools and systems do not need to become embroiled in academic arguments about middle and teacher leaders.

It is also important to remember that contextual differences within and between countries in terms of how schools are structured and resourced mean that teacher and middle leadership ideas may not be relevant in all contexts.

In this final section, policy recommendations, practice recommendations and future research directions are provided.

5.2. Policy Implications and Practice Recommendations

The definitional clarity of the middle leadership research gives it authority that is lacking in the more definitionally contested teacher leadership space. This authority was used to frame a set of six trustworthy claims described in this paper, with these claims covering both middle and teacher leadership across their impact on students, teachers and schools; the interventions they use to promote improvement; balancing leadership and management through high expectations and role clarity; identifying middle and teacher leaders; supporting middle and teacher leaders; and avoiding the factors that diminish the work of middle and teacher leaders.

Table 2. Policy implications and recommendations (in applicable contexts).

Area and Claim	Policy Implications	Practice Recommendations
Teacher and Middle Leader Definitions. Claim 1: Teacher and middle leadership are not the same concepts, although their might be overlap depending on how they are defined. Teacher leadership is mostly about the work of teachers who exert influence on teachers and the school beyond their teaching work, and these people do not have a formal leadership or organizational role outside of their teaching. Middle leadership is mostly about teachers who also have a formal leadership or organizational role, and exert influence on teachers and the school.	Understanding and clearly describing the career stages and work of teachers and school leaders is important and needs to be incorporated by education systems into how they think about their teacher workforces.	Both teacher leadership and middle leadership conceptions be used to frame how the work of teachers and school leaders in an educational jurisdiction is described. Teacher leadership should be associated with teachers without formal organisational roles, and middle leadership with teachers with an additional formal organisational role.
Impact Claim 2: Teacher and middle leaders can impact significantly on students, teachers and schools.	In many jurisdictions, teacher and middle leaders will be key players in school and system success, and systems should be actively developing and supporting these roles in schools where possible and appropriate.	Systems and school leaders need to actively support the development of teacher and middle leaders so that their work impacts students, teachers and schools.
Interventions Claim 3: The way middle and teacher leadership is enacted varies across contexts, but there are consistent elements that include improving teaching and learning, working collegially with colleagues and fostering collective endeavour, improving school conditions and being critically reflective about what schools do.	Teacher and middle leadership needs to be part of how systems conceive of schools and the career progression of teachers.	Systems need to develop models/conceptions/standards that help describe outstanding middle and teacher leadership work.
Leadership focus Claim 4: Middle and teacher leaders can have a leadership focus when there are high expectations and role clarity in regard to this work.	Systems need to incorporate a leadership focus into how teacher and middle leadership is conceived.	Systems need to develop models/conceptions/standards that clearly describe the leadership work of middle and teacher leaders.
Identification Claim 5: Leadership preparation needs to begin in initial teacher training, and then leadership skills, qualities and dispositions need to be developed and supported through teacher, middle and senior leadership phases.	Systems need to have leader identification and support strategies and services in place for all career stages.	Systems need to develop leadership identification and support programs and processes that address all stages of teacher and school leader career progression.
Supports and hindrances Claim 6: Teacher and middle leadership work can be supported through developing leadership expectations in teachers, providing leadership preparation and development programs, ensuring work roles are well defined, having both leadership and management expectations, having a supportive school culture and structure, and having the support of the principal and other senior leaders. The absence of these diminishes the work of teachers and middle leaders.	Systems can be more proactive in how they support the work of middle and teacher leaders, including role clarification, provision of professional learning, engaging principals and other school leader support, and fostering school cultures and structures that support and value the work of middle and teacher leaders.	School leaders need to clearly define the work of middle leaders and include explicit leadership expectations and provide active support professional support that includes professional learning and supportive school structures. Middle leaders need to be proactive in their own professional development. School leaders need to recognise and nurture teacher leadership and provide appropriate professional learning support.

shows policy implications and practice recommendations for these areas (hindrances are combined with support and related definitions are included).

5.3. Reflection on Future Research

Gurr and Nicholas [82] considered future research directions for teacher and middle leadership, and this section draws upon this writing.

Perhaps the contemporary reality of many schools, with increased use of collegial/collaboration arrangements (e.g., [83]), means that dividing leadership research into principal, senior leaders, middle leaders and teacher leaders and focusing on the distribution of leadership, is no longer sufficient. More holistic research is called for, and this may benefit from a practice focus such as the interaction perspective of distributed leadership researchers (e.g., [84]) or the practice architecture approach favoured by Grootenboer and colleagues in their research on middle leadership (e.g., [10,44,85]). This will likely require innovative research strategies that can, in unobtrusive ways, collect rich practice data. In terms of ways to conceptualise middle and teacher leaders, whilst general leadership models can be adapted and used to locate their work (e.g., [12]), there are middle [8,9] and teacher (e.g., [2]) leadership models and practice community views (e.g., [86]) that are likely to become important to gain a better understanding of the work of middle and teacher leaders.

Another way is to consider ways other than the division between teacher, middle and senior/principal leadership. In this regard, the research of Nicholas [87] holds promise. From his interview and network analysis research of distributed leadership in three successful secondary schools, Nicholas [87] developed a distributed model of influence (DMI), which described how the extent of an individual’s leader influence is dependent on their positional power and personal connectiveness; the model is shown in Figure 2.

Nicholas ([87], p. 213) described the model in this way:

‘At the centre of the model is a triangle which represents the leader/follower/situation triad…Situation and followers are located at the bottom vertices in the blue bar, and the leader (or leader influences) is located at the top vertex. Running vertically through the middle of the triangle is a line which represents the level of influence. Leader influence is indicated in grey at the top of the line and is concerned with leadership practices associated with capacity building, decision making and organisational change. High levels of influence will utilise all three practice areas more often.

There are two components to the model which impact leader influence, and these are Positional Power (yellow) and Personal Connectiveness (green)…

Positional power was viewed as deriving from organisational factors, including leadership structure, organisational strategy and organisational planning. Personal connectiveness was viewed as deriving from individual-level factors, including knowledge, skills, expertise, relationships, support and trust. Leader influence was exerted through practices that included capacity building, decision making and organisational change.

In the DMI, the highest levels of influence come from being high on both positional power and personal connectiveness. Someone with high positional power and low personal connectiveness will have a middle level of influence, as would someone with low positional power but high personal connectiveness. Importantly, for this chapter, it helps to distinguish between teacher leaders and middle leaders. Teacher leaders will be those teachers with significant classroom responsibilities and no formal organisational position. They will be low to moderate on positional power because of the lack of a formal organisational position but high to moderate on personal connectiveness. This definition covers those teachers who might be involved over a short time period in an initiative that gives them some positional power, but most of their leadership influence will come from their personal connectiveness—their knowledge, skills, expertise, relationships, support and trust. Middle leaders will be those teachers with significant classroom responsibilities and a formal organisational position. They will be moderate to high-moderate on positional power because of their formal organisational position, and they will likely be moderate to high on personal connectiveness if they have been developed, selected and supported appropriately.

The DMI also allows for consideration of other typical roles in schools, such as principal, and roles that will be more context-dependent. For example, in the USA literature, there is often discussion of roles like math or literacy coaches or specialists in support areas [6], and in Chile, as mentioned earlier, there are Technical Pedagogical Heads who lead the curriculum and support the principal [57]. These positions are not found, or not prominent, in other educational jurisdictions. These people typically have none or limited teaching responsibilities, yet their moderate to high-moderate positional power means that they are often not considered to be part of the senior leadership or principal class in a school. The DMI, of course, covers principals and other senior leaders whose positions have high positional power and accounts for variation in their influence based on their degree of personal connectiveness.

The DMI accounts for variation in the distribution of leadership through formal positions across senior and middle leaders in schools and accounts for others, like teacher leaders, who do not have a formal leadership role but are nevertheless widely influential in schools. It also provides clarity about teacher and middle leaders based on positional power and personal connectiveness. The DMI is not the final answer for the problems in researching middle and teacher leadership, but it does provide a conceptual model for thinking about better ways to describe middle and teacher leaders so that the research about them is more distinct. Indeed, the DMI might be a better way to conceptualise the leadership work of anyone in schools. More research on the model is needed, and this could be a rich case study and mixed-method research that captures the complex nature of contemporary schools and the work of school leaders.

5.4. Conclusions

The research on middle and teacher leadership is rich and complex, and both areas are expanding in terms of the volume of research and the variety of contexts reported on. The work of these people in schools is important, and it seems likely that this importance will increase as schools across the world become more complex. Understanding the work of middle and teacher leaders within contexts is important as contexts vary greatly. Despite conceptual difficulties, it seems to be imperative that school systems consider these roles and, if contextually appropriate, actively seek to develop and support these roles. Considering teacher and school leader career progression within a system, identifying opportunities for teacher and middle leaders, and then supporting them to be leaders, is likely to enhance school and system success.