Creating and Developing a Collaborative and Learning-Centred School Culture: Views of Estonian School Leaders

The present study aims to analyse how school leaders perceive their activities in creating and developing a collaborative school culture that promotes the school learning process. The data were collected in semi-structured interviews with nine school leaders and analysed using thematic content analysis. The results revealed that only three of the school leaders focused on the shared values and shared leadership necessary for creating a systematic and analytic approach to organisational and teacher development. The school leaders understood the importance of leading the development of the learning process, but this did not take place as expected in practice. Organisational and teacher development seemed to be unsystematic or not based on the continuous monitoring of processes. The findings of our study indicate that development programmes for school leaders should concentrate more on shaping the views, knowledge and skills needed to develop a collaborative and learning-centred school culture.


Introduction
Previous research has demonstrated that changes in teaching do not occur if the organisation is not oriented to the learning and development of its members (Opfer et al., 2011). The collaboration of teachers influences the quality of teaching and consequently the learning outcomes of students. However, such collaboration depends on whether the school management has created favourable conditions for it to thrive (Kruse & Louis, 2009;Woodland et al., 2013). Estonian schools provide interesting contexts to study leadership, as they show high academic performance and achievement levels in international assessments, such as PISA (OECD, 2019). Interestingly, however, the Teaching and Learning International Survey (TALIS) (OECD, 2014) points to a poor culture of collaboration among teachers and a lack of substantive feedback on their teaching activities. Although not designated as head teachers, Estonian school leaders have a high level of autonomy, with authority to appoint and dismiss staff, negotiate working conditions, and make decisions about school finances, educational priorities and development plans for the school (Estonian Parliament, 2010). They are the main actors in designing the school curriculum, which is based on the national framework, and in supporting teachers' professional development in order to implement changes. At the same time, based on the TALIS 2013 survey, only 7% of Estonian school leaders regularly visit lessons to observe and monitor learning processes (the TALIS average is 49%), while 41% of school leaders develop measures to support teacher collaboration on new teaching methods (the TALIS average is 64%). In order to gain a clearer understanding of the contradictory results referred to above, we decided to explore school leaders' views on their activities in creating and developing a collaborative school culture within their everyday leadership practice. This is particularly pertinent considering that the Estonian Lifelong Learning Strategy (Estonian Ministry of Education and Research, 2014) and the Estonian school leader's competence model (Innove, 2016) emphasise the school leader's essential role in leading changes and developing a leadership style that focuses on the development of learners, teachers and all school personnel.

The school leader's role in creating a learning-centred collaborative school culture
A collaborative school culture that focuses on the improvement of the learning process has been addressed by researchers for a long time. Such a culture makes an important contribution to both the success of the school improvement process and its effectiveness (Campo, 1993;Fullan & Hargreaves, 1991), creating an environment in which changes are faster, problems are solved together, and teachers support each other (Eisenschmidt et al., 2015). It has also been realised that a collaborative school culture helps teachers to increase their self-esteem and self-confidence, take responsibility for managing various situations (Angelides, 2010;Kohm & Nance, 2013), and find additional meaning in their work (Kruse & Louis, 2009). School leaders play an important role in creating a school culture that values collaborative learning by providing time for teachers to do research, plan and design together. Researchers have identified that the school leader's support for and participation in the professional learning of teachers is the most significant means by which school leadership impacts student learning (Robinson et al., 2008). A collaborative learning-centred school culture provides a climate and structure that encourages teachers to work with each other, fosters staff learning and professional growth, and benefits all members of the school community.
Research into school leaders has highlighted various strategies and opportunities for making a school culture more collaborative (Day & Sammons, 2006;Hallinger, 2011;Leithwood et al., 2008;Liu et al., 2016;Sales et al., 2017). Based on earlier research, we can point out four key activities in developing learning-focused leadership and collaborative school cultures: (a) building a shared vision and setting goals; (b) sharing responsibility and creating an environment for collaborative learning; (c) improving the quality of teaching and learning; and (d) modelling and building trusting relationships within the organisation (see Table 1). Building a shared learning vision and goal setting reflects the extent to which school leaders articulate and communicate an inspiring vision that motivates learning in the school (Liu et al., 2016). Creating and communicating a shared vision in dialogue with the members of the organisation is a foundation for effecting changes in an organisation (Kruse & Louis, 2009;Leithwood et al., 2008). Efficient school leaders who share the school vision are always visible in the school building: they go around and talk with teachers, give feedback about the latest developments, set new development goals, and create a feeling of success by giving positive recognition (Barber et al., 2010;Engels et al., 2008), thus fostering ownership of the directions for development. Researchers have stressed the significance of clearly communicating values and directions of development (Day & Sammons, 2006). However, it is important that the vision is also operational, that is, openly formulated as explicit and clear activities in the development plan of the school. In addition, these goals and activities should constantly be kept in mind when making choices and decisions (Youngs & King, 2002).
Convincing research has shown that sharing responsibility is one of the essential steps for creating a collaborative school culture (Vangrieken et al., 2015). Shared responsibility and expertise encourage the sustainability of changes, enabling the changes to have a more solid footing (Harris, 2005;Heck & Hallinger, 2009). Implementing shared leadership presupposes shared goals and a favourable working climate, ensuring time for teachers to get together and benefit from the school leader's friendly and supportive attitude (Bush & Glover, 2014). Thus, the leader's role is to create a hospitable environment, devote time and space to collaboration and sharing expertise, provide resources, and support the implementation of teacher learning (Barber et al., 2010;Hallinger, 2011;Kruse & Louis, 2009). A school culture that is based on open communication and flexibility allows teachers to participate in decision making and express their opinions, thus increasing their feelings of control in work engagement (Zahed-Babelan et al., 2019). Empowering teachers' learning communities and working groups (although professional learning communities can include members from outside the school, e.g., parents, staff from other schools and external stakeholders) supports teacher leadership and plays a crucial role in improving the quality of teaching.
In order to improve the quality of teaching and learning it is essential that the main process of learning is constantly and consistently planned, monitored and analysed in light of the shared goals. Research has shown that student achievement is higher when the school leader focuses on developing and leading teaching and learning at school (Leithwood et al., 2008;Robinson et al., 2009).
Effective leaders pay attention to teaching with a particular focus on student learning. They devote as much time as possible to supporting teachers in their efforts to strengthen teaching and learning in the classroom. They monitor the process and collect evidence to provide feedback to teachers in order to ensure that high quality and alignment between learning goals and classroom instruction is maintained (Murphy et al., 2007). Instructional quality can be strengthened by systematically supporting teachers' collaborative planning, evidence-based practice development, reflection and mentoring (Robinson et al., 2008;Lai et al., 2016). Thus, we can say that school leaders who see themselves as pedagogical leaders focus first and foremost on developing and guiding the learning process (Bush & Glover, 2014;Hallinger, 2011;Hallinger et al., 2017). Researchers have observed that one important aspect through which school leaders influence teacher commitment to change and professional learning is gaining their trust in the school vision and leadership Tschannen-Moran, 2009).
Modelling and building trusting relationships highlights the role that school leaders play in supporting the values of openness, risk-taking and collaboration in their own behaviour (Hallinger, 2011;Leithwood et al., 2010). Research indicates that trust develops between school leaders and teachers when the school leader's beliefs and actions are consistent with school goals, when school leaders share responsibility and support teachers' work, and when they manage conflicts proactively and effectively (Youngs & King, 2002). In other words, trust favours effecting changes, but well-managed and successful changes also build up trust in the school leader. School leaders cannot build trust simply by talking; it must be seen in their actions (Kruse & Louis, 2009). By creating a climate of psychological safety, leaders can increase learning (by learning from mistakes and failures) and encourage teachers' creativity and their readiness for risk-taking in implementing novel ideas in their teaching process (Yukl, 2012). Trust and a supportive working atmosphere in which school leaders model learning leadership and help other leaders and teachers to grow are considered important traits of a learning organisation (Bruggencate et al., 2012).
In order to understand how Estonian school leaders perceive their role in fostering the learning process at school, we seek the answer to the following question: How do school leaders view their activities in creating and developing a learning-centred collaborative school culture?

Sample
School leaders who had participated in a large-scale survey conducted in Estonian schools in 2017 were invited to participate in a qualitative study. Nine school leaders agreed to take part: five of them were men and four were women, and they were all aged between 30 and 60 years (see Table 2). Their work experience varied from one to thirteen years. The type of school varied from preschool/primary to upper secondary school (grades 10 to 12), and the number of students in the schools varied from 208 to 1520.

Data collection and analysis
The data were collected using semi-structured interviews. The questions were compiled based on interview questions devised by Nevgi and Korhonen (2016), which focus on mapping and analysing the leadership styles of middle managers at universities, and adapted to the context of Estonian schools. In the present study, we focused only on the questions concerning the school leader's perceptions of their role and activities in developing a learning-focused collaborative school culture. The questions focused on: (a) organisational culture (e.g., How would you describe the work culture of your organisation?); (b) leading the learning process of the school (e.g., What is your role and what are your goals as a leader in pedagogical development? What do you view as the changes that need to be implemented in this regard?). A more detailed overview of the questions used in the study is provided in Appendix 1.
The duration of the interviews varied from 53 minutes to 1 hour and 33 minutes. The interviews were transcribed and analysed using thematic content analysis (Braun & Clarke, 2006). The unit of analysis was a complete answer or single sentences, or sets of sentences that expressed a conceptual whole. A deductive approach was used: a list of key activities for supporting learning and a collaborative school culture (see Table 1), compiled based on the texts, was used to structure the analysis. The interviewees' responses were analysed based on this list, and similarities and differences in the school leaders' patterns of behaviour were mapped. In the first phase, the first author undertook the initial data analysis. In the second phase, the themes and codes were reviewed by the second author and the reliability of the coding was checked. During mutual discussions, disagreements were discussed until the researchers reached a common interpretation of the coding.
Excerpts from the interviews with the school leaders are provided with the corresponding school number (see Table 2) in order to distinguish the views of different school leaders.

Building a shared vision and setting goals
An analysis of the school leaders' key activities supporting a learning-centred and collaborative school culture reveals that although five school leaders clearly stated that their schools do have a vision, only in three schools does this vision actually serve as the foundation for daily decision making and activities: "…what is important for us at the moment and what is not. What do we do, and what don't we do, what is relevant and what is not…" (7). In this case, the role of the school leader is described by one of the school leaders as: "Seeing the big picture. Whether something is not right, whether something needs to be changed, or maintained /.../ and for understanding, if it gets too tight somewhere you need to look at those main documents all the time /.../ the vision has already been created, and the main direction has been set, but now it is about how we get all those wobbly things better..." (9). The need for constant communication is viewed as follows: "…we know our vision and our direction in the sense that I see it like this /.../ I simply explain, or at least it seems to me that I have to work at it all the time" (8).
In the case of four of the school leaders, the shared values and long-term goals that they aim to achieve remained unclear: "...maybe this vision for the future and what happens, but as I said, it is kind of a vague situation" (3). "I don't, uhm, create this vision by myself, it has to come through someone else (4)".
The school leaders claimed that they aimed to make and maintain changes, but what those changes were remained unclear. Two of the school leaders admitted that the school development plan had a life of its own, so to speak, and administrative duties did not leave enough time to take the initiative; consequently, the school leader's essential role in communicating the vision remained largely unfulfilled. Five of the school leaders mentioned that they do not manage to "get around and about the school" (2) as much as they would like and be visible to the teachers as much as needed. Nevertheless, when it comes to implementing the vision in practice, the shared understanding of the entire team plays a significant role. If the vision is not shared by everyone, then it may happen that: "…head teachers move things in a different direction, the goals of the development plan are not actualised, or only some people contribute" (1).
Thus, the interviews reflected the tendency for school leaders to become dissatisfied with the work of the management team in schools, which either lacked clear direction and strategic goals, or in which the aims were not sufficiently communicated and not used in everyday decision-making and operating processes.

Sharing responsibility and creating an environment for collaborative learning
The second key activity for a learning-centred collaborative school culture is related to joint decision making and shared responsibility. The interviews revealed that in most schools, the responsibility for pedagogical development was delegated to head teachers. School leaders saw their role rather as that of a generator of ideas and a discussion partner: "...I think that my role is about letting the others know when I hear about innovations /.../ then I create the opportunity for the head teacher" (5). One school leader considered their own role to be mainly about managing finances: "...I tell them all the time in the teachers' council /…/ that you are top specialists, I am not managing your time, I am managing finances, those things, so that you do the things that we have agreed on together..." (1). Only two leaders said that they had a close collaboration with the head teacher in substantively developing teaching and learning processes. However, these school leaders also mentioned that their long work experience as a head teacher made it easy for them to have this collaboration.
Based on the interviews, it seems that shared leadership works mostly from top to bottom, meaning that the management assign a task, propose an idea, and lead the formation of working groups. On the one hand, the school leaders expected the teachers themselves to show more initiative and take responsibility: "...I wish there were fewer questions about how to do this or that and more about what needs to be done; at the moment, the way it works is that once you set up a task the next question is how are we going to do it /.../ Kind of taking responsibility..." (2). On the other hand, not enough opportunities were given for such initiative, as the processes were lead from top to bottom.
Teachers' lack of initiative may also be due to vague development goals, which influence motivation as well as the feeling of ownership of innovations. Here, the school leaders with a clear vision of strategic goals clearly stood out: "…things like 'I got this really great idea, let's do it like this now!' just don't work. You've got to talk about it first, in an information meeting, for example, that I've got this idea, and how I came to it and why it came or how we could get it, whether someone sees any obstacles, then it becomes like everyone's idea. So, then we can get on with it, or I get some feedback that: 'Come on, don't mess around, that's totally irrelevant' or 'That's not okay' or 'Let's think about it... ' and so on..." (7). In these schools, joint discussions were organised and decision making on new initiatives and activities was broad-based.
In the interviews, all of the school leaders mentioned regular meetings for sharing daily information, but in two schools there was also a longer meeting for joint discussions. In the words of one school leader: "…last year we created a collaboration day /.../ when everyone said that we don't have time to meet /.../ and don't find the place, then we'll do it this way by making a collaboration day, and this collaboration day is Monday; on this day nobody leaves the school before half past three" (2). It is important for the school leader to create opportunities for collaboration and provide teachers with the time and space for sharing experiences and planning their activities together. This not only creates a favourable environment for collaborative learning, but also supports joint decision making. When teachers are involved in the decision-making process and understand the goals of planned activities and consider them meaningful, they are more likely to contribute to these goals. When the strategic goals are unclear, the teachers seem to try everything (e.g., participate in projects, test different methods, etc.), but the usefulness and sustainability of it all remains weak. "Then we've had learning via Skype /.../, integrated learning, we ordered an external lecturer for that... Then we've tried open education... We've also done lots of these kind of days of integrated learning to get teachers working together, to get them to mix and mingle, participating in projects, so we've had project days with different schools and we've also done a lot of outdoor learning days, internally, kind of collaboration days /.../ so we try to bring in these new methods every way we can..." (5). Agreeing with every small change without any clear goal fragments teachers' capacity to work and decreases their motivation.
Only three of the school leaders reported involving teachers in implementing changes in which teachers' opinions were important. In these schools, teachers were also more proactive, and the leaders were more satisfied with teacher collaboration.
Interestingly, only one of the school leaders described how students were also involved in leading the school and how realising the development goals of the school was supported through the student council: "…through the student council, time after time we try to remember, that you know, we've got this development goal (students taking responsibility for learning), and think by yourselves now how can you talk to the students, how can you first assume the right attitude yourselves and in this way influence the opinion of others..." (9). The student council was involved in establishing differentiated pay for teachers: "I allowed the students to discuss how the school leader should assess teachers contributions..." (9).
To sum up, if the vision is vague (or there is none) and values are not dealt with, they are not sufficiently discussed and shared. This results in teachers feeling less responsible for changes and showing little initiative for collaboration, while their activities are fragmented and random. Although learners' development and shaping an environment conducive to learning was important for all of the school leaders, the development goals in most of the schools were unclear, and leadership was shared only among the management team. The interviewees described many different activities and projects, but it remained unclear why and how these undertakings helped to achieve the development goals. In addition, it seems that although there were systems for sharing everyday information, few of the school leaders had created favourable conditions for teachers' collaborative learning; for example, effective forms such as mentoring and co-teaching were not mentioned by the interviewees.

Improving the quality of teaching and learning
The quality of education depends on teachers' competence; therefore, improving the quality of teaching and learning is one of the most essential tasks for a school leader. However, it seems that only three of the nine school leaders included in the survey had a systematic approach to supporting teachers' professional development. These leaders mentioned appraisal interviews, lesson observations, giving feedback, and interviews based on teacher's self-assessment (the latter were also used for choosing training courses). Even though all of the school leaders talked about teachers' training needs and joint training, it remained unclear how these decisions were taken, or as one school leader said: "...this kind of constant training and this is what we do, but I am not saying that it is very systematic and planned or something..." (4).
Most of the school leaders emphasised teachers' freedom in choosing training courses. Nevertheless, too much autonomy may not support teachers if they lack a feeling of competence or connection: "…people are kind of autonomous in the choices about self-development, like you can do what you want, you are a professional /…/ But sometimes, what comes along with it is that people feel a bit left alone, in the sense that the whole subject-field is on your shoulders. This is your business. And then when something gets weird, then there will be this kind of insecurity, I mean this system suits strong personalities..." (6). It remained unclear how teachers made their choices, as most of the schools included in the study did not have a feedback system for teachers and lacked collaboration, while only four of the school leaders mentioned having developmental discussions.
A learning-centred school culture presupposes the constant monitoring of learning processes, data collection and analysis. However, only one of the school leaders highlighted the necessity for monitoring and collecting data to establish future directions in order to improve the learning process: "…it's a matter of long-term perspective /. give an insight into such things" (7). It can be said that the interviewed school leaders had a limited awareness about evidence-based leadership in school development; decisions and choices were made based on instincts rather than analysis of data.
Constant improvement of learning assumes that teachers receive feedback on their work. Among the studied school leaders, three stood out: in these schools, teachers received feedback via developmental discussions and lesson observations. In this regard, one of the school leaders, who was talking about developing a feedback system, commented: "The thing with feedback systems is that you've got to be very careful when implementing them because at a certain point people get the feeling that they're going to check us. It's very much like a kind of fine mechanics..." (6).
We can nevertheless conclude that improving the quality of teaching and learning was generally implemented in a chaotic manner in the schools studied. Processes of monitoring trends and collecting evidence in a more informed manner took place in only one school. Providing feedback for teachers and supporting their development seems to be random or largely the teachers' own responsibility.

Modelling and building trusting relationships
All of the school leaders emphasised the significance of relationships and had made efforts to improve relationships in their schools. However, the leaders' behaviour differed, and those in organisations where good relationships were valued clearly stood out from the others. The team was harmonious and teachers showed considerable initiative: "...our teachers-staff members are really great leaders, as a teacher should be, and they often love to take the leader's role and implement their ideas' (9); "...I absolutely love these moments when we are all together and do some things together, I mean the kind of nice things of being and doing things together, whether it's sports day or some excursion or our school assemblies..." (7).
However, several of the school leaders expressed scepticism regarding teachers' readiness and willingness to collaborate: "...collaboration between people is so scattered" (3). Others admitted that these processes had not gained ground as expected: "But I think that one thing we haven't got running very well is the kind of working groups that do something throughout the whole year" (6).
Top-to-bottom initiative does not increase teachers' trustful relations: "…project day, this forces them again into some kind of collaboration. But well, we do have some bottlenecks, where nobody really wants to take responsibility for organising these project days /.../ so what we do at least is that we plan these things until the end of the school year, who does what, and topics are also more or less settled, but who leads this, who takes responsibility, like everyone does it, but in the end, it's the same people who do it' (4). For motivation, it is essential that teachers sense the support of colleagues and management, the necessity and usefulness of changes in their daily work, and freedom of choice and opportunities, i.e., autonomy. In order to inspire teachers to develop their practice and try new things, the environment must be conducive to learning, as one school leader emphasised: "…we allow a child to make mistakes, right, because through mistakes we learn; the same applies to all of us, that we all still make mistakes from time to time" (8).
The importance of recognition for a supportive school climate was especially stressed by one of the school leaders: "...we talk about things a lot. And it starts with the fact that we have long information meetings twice a week, 40 minutes, and there we haven't got this kind of boring and dry information sharing, but rather people talk about what they have done, where they have been with their students, how these events have succeeded, what results students have achieved in competitions, and the head of the school also has an opportunity to praise everyone, and by the way, the employees really like it, the fact that they are recognised right there in front of their colleagues" (7).
It is also crucial for a school leader to be a pedagogical role model. As one of the school leaders said, his/her goal was to show that achieving certain development goals is possible for teachers: "...firstly, I became a class teacher. I will show them that appraisal interviews and forming bonds is my first priority" (1). Another leader emphasised the need to be updated and not to lose contact with teachers and students: "...I want to be in front of the class for exactly this reason so that I would not lose touch with students or with teachers...otherwise, we would become distant" (7).
Leaders should contribute to the development of trusting relationships by serving as an example when communicating with colleagues and students. As one of the school leaders noted: "We are all different /…/ it isn't only important that we say that we care; it also needs to be obvious, people need to feel that they are cared for. Whether you are a child or an employee or a parent…" (8).
Based on the analysis of the interviews, it seems that the relationships are better, and the willingness to collaborate is greater, in schools where the goals are clear and shared among the staff. Clear goals increase trust in the leader and collaborative activities are more focused, thus increasing teachers' willingness to take the initiative in the school's development. It could be assumed that school leaders' work experience or school size could influence the quality of leadership activities and the ability to create a shared vision and a collaborative learning-centred school culture. Surprisingly these patterns did not emerge in the results. The results of our study confirm those of other studies that found that there are more differences within the studied school leader group than between groups with a different level of experience (e.g., Barnett et al., 2012). Specifically, the views of the three school leaders with only 1-2 years of experience differed significantly: only one of them viewed the role of the school leader as mainly managerial, while the other two viewed the role primarily as a shaper of collaborative school culture and a substantial leader in school development. As this study focused primarily on school leaders' perceptions of the leader's role, further research is needed to determine the extent to which the ideas reflected in the interviews are realised in everyday school management activities.

Concluding remarks and further perspectives
A collaborative school culture presupposes shared goals and responsibility, encouraging teamwork and relationships, supporting everyone's development, and providing feedback and recognition in an atmosphere of trust. To summarise the findings, it appeared from the interviews that even though all of the nine school leaders included in the study valued collaboration and high-quality teaching and learning, only three of them had a clear vision and goal that was actually used as the basis for everyday decisions. The leaders who had a clear vision for school development supported collaboration in a more systematic and diverse manner, and described a well-functioning team and close collaboration in the school. An unclear and blurred perception, however, leaves space for uncertainty and irresponsibility. Therefore, the leaders who did not have a clear vision were mainly sceptical about the relationships between the teachers and described teamwork in their school as meagre. Even though these school leaders believed that teamwork was crucial, it remained unclear why that was the case and what could be done to improve the situation. The ability to create and communicate a shared vision, and to give meaning to it through actions, is considered one of the characteristics of an effective school leader (Leithwood et al., 2008;Kruse & Louis, 2009).
The role of leadership in shaping a collaborative school culture should not be underestimated, as it encourages sharing responsibility (Vangrieken et al., 2015) and promotes the sustainability of changes (Harris, 2005). From the interviews, it appeared that all of the school leaders exercised shared leadership to some extent, although it was frequently used in a top-to-bottom manner and without much thought on how to increase teachers' motivation and involvement in daily school management. If responsibility is shared, it is more likely that the organisation can guarantee professional development at the organisational as well as the individual level. Forming working groups inside the organisation is one way to develop relationships and increase the effectiveness of collaboration, and to support teachers' professional development (Kruse & Louis, 2009). All of the leaders pointed out that team training sessions and excursions were organised in their school to a greater or lesser extent. At the same time, supporting teachers' professional development was unsystematic, and the formation of working groups tended to be a management initiative. There needs to be an increase in school leaders' knowledge and skills regarding the creation and support of learning communities, and the strengthening of teacher agency and motivation to work in such communities.
If the goal is to change the school culture, it is essential for leaders to have a better understanding of their role in leading the main process of a school, that is, the learning process. Leading and developing teaching and learning is the main focus of a pedagogical leader; in the present study, this was most clearly seen in the case of three of the school leaders. Moreover, the data of TALIS 2013 indicated that school leaders who focused more on supporting teaching and learning were more likely to take specific measures to influence teachers' work and careers (Übius et al., 2014). Although the school leaders in the present study felt that changes in the learning process were necessary, most of them delegated the task of developing the learning process to the head teacher. It is very likely that this is because such tasks have traditionally been the duty of the head teacher in Estonian school culture.
In order to develop the learning process in school, leaders should gather and analyse data to make decisive changes. Only one of the school leaders talked about the importance of research, evidence and data analysis in making decisions about long-term development strategies, as well as everyday teaching and learning. Nowadays, capacity building, inquiry-oriented practice, and data-driven decisions are considered to be central themes of educational improvement (Hargreaves & Shirley, 2012;Louis & Stoll, 2007). Teachers should therefore also be informed about what kind of evidence they should collect so that the effectiveness of the practices implemented can be analysed (Datnow, 2011).

Practical implications for strengthening collaborative learning-centred school leadership
Based on the interviews, school leaders need support and training in two particular areas: 1) creating a shared school vision and putting it into practice; and 2) acquiring the knowledge and skills required to systematically improve the quality of learning and teaching.
Development programmes for school leaders should support them in developing a pedagogical vision and should provide tools for collecting data and analysing the progress towards the established goals. With regard to practical measures, implementing school leaders' self-assessment as a part of internal assessments of schools should be considered, in addition to training and development opportunities. There are different self-assessment models available aimed at helping educational leaders to assess their personal mastery (e.g., Gregorzewski et al., 2018) and to analyse their activities with regard to the school's development goals, in order to gain feedback on their work and professional development.
Another aspect that should receive more attention in the training of school leaders is how to enhance teachers' professional development so as to increase school capacity and accomplish organisational goals. According to the present study, some school leaders seemed to believe that their role was mainly to find resources to implement a variety of innovations, but they failed to see that this kind of approach -introducing multiple forms of new initiatives without a clear vision -leads to a fragmented set of chaotic activities that are unable to support teacher motivation, commitment and learning. Development programmes for school leaders should therefore place more emphasis on how to enhance schools' capacity to build a shared commitment to school goals, and to create structures and work conditions that systematically promote teacher collaboration and learning. The dimensions and practices associated with collaborative and learning-centred leadership in this study may offer a starting point in this regard.
The limitations of the present study clearly suggest an opportunity for further research: the interviewees' answers may not have reflected all of the activities undertaken in their schools. A more broad-based study should therefore be conducted among school leaders in order to gain a deeper insight into the main challenges for school leaders in developing a collaborative school culture.

Biographical note
Katrin Poom-Valickis, PhD, is a professor of Teacher Education at Tallinn University. She has been a project leader and co-coordinator in several projects related to the development of Teacher Education and member of the expert group who prepared the implementation of the induction year for novice teachers in Estonia. The main research interest is primarily focused on the teacher's professional development, more precisely how to support future teachers' learning and development during their studies and first years of work.
Eve Eisenschmidt, PhD, is a professor of Educational Leadership at Tallinn University. Her research areas are the professional development of teachers, school development and leadership. She has been active in development of teacher education policy on the national level, e.g. preparing the implementation of the induction programme for beginning teachers in Estonia and developing initial teacher education programmes at the university.
Ann Leppiman -M.A. in Educational Leadership. Ann was working 2017-2020 at Tallinn University as development manager for academics. Currently she serves as an adviser for the minister of Ministry of Education and Research. Ann's research interest is connected with school leadership and school culture, pedagogical development and support for academics.