The Proliferation of Lesson Study for English Language Teachers: A Meta-Synthesis Study

Although studies on the lesson study experiences of English language teachers have increased in Turkey in recent years, there is still a need for further studies on integrating the model into the context. This study examined qualitative research on the lesson study conducted with English language teachers in Turkey. It was aimed to reach a synthesis to ensure the proliferation of the model. The common databases were searched with particular keywords, and specific inclusion criteria were used. Selected studies were scored with a checklist to evaluate quality, and eight studies (six articles and two doctoral dissertations) that received the required score were included in the research. The analysis followed the development of the first and second-order themes, interpreting and synthesizing. The common findings in the studies show that the lesson study provides significant contributions to English language teachers despite the difficulties in the process. The synthesis includes the initiatives at the individual and institutional dimensions. It is concluded that English language teachers' pedagogical design capacity and collaboration skills should be strengthened at the individual dimension. At the same time, administrator, mentor/facilitator support should be provided, and policy changes should be made in teacher education at the institutional dimension. We also recommend examining how the model can be adapted to Turkey's cultural-educational context, teacher autonomy, and identity.


Introduction
Lesson study, originating in Japan, is one of the professional development (PD) models providing job-embedded and active involvement for teachers, and it has recently gained popularity in many countries.Based on Vygotsky's (1978) Sociocultural Theory, lesson study entails teachers working together with their colleagues to seek solutions to educational problems (Shabani, 2016).In this process, teachers collaboratively design instruction, implement, observe, discuss lessons, and give 11(2), 2021, 261-286 www.ijocis.comfeedback to make lessons more effective (Dudley, 2015;Lewis, 2000;Lewis, Perry, & Hurd, 2009).Alternatively, teachers make a nexus between theory and practice, analyze their classroom practices in depth based on theory, be reflective and work collaboratively (Orland-Barak & Maskit, 2017).

International Journal of Curriculum and Intructional Studies
The lesson study begins with defining a problem that teachers have identified collaboratively (Dersforges, 2015).Then, research is conducted on teaching materials and suitable methods for the subject (Takahashi & Yoshida, 2004).A research lesson (usually three) is designed for the problem.In research lessons, other teachers take on the role of the observer while a teacher is teaching (Dudley, 2015).In the observation phase, which is the essence of lesson study (Doig & Groves, 2011), teachers record what students say, how they use the materials, and where they have difficulties (Lewis, Perry, & Hurd, 2004).Finally, there is a discussion about the research lesson.While the discussions usually involve the lecturers' and observing teachers' meetings, an outside educator or researcher may also attend these meetings (Lewis, 2000).
Even though lesson study has a well-established history, it relatively newly finds an echo in Turkey in other educational settings.Eraslan (2008) discusses it for the first time in the context of Turkey, and he states that the model contributing to the PD of teachers should be used in Turkey as well.The model generally focuses on mathematics education (i.e., Özdemir Baki & Işık, 2018).There are, however, examples in primary school education (Ayra & Kösterelioğlu, 2021;Gözel, 2017), art education (Hiçyılmaz & Aykan, 2020), and preschool education (Tepetaş & Tezcan, 2020).Besides, its use is becoming more widespread among English language teachers (e.g., Bayram & Canaran, 2019;Gök, 2016;Orhan, 2020) and teacher candidates (Demirbulak, 2011;Yalçın Arslan, 2019).All these studies are within the scope of graduate theses or scientific articles; no attempts by the Ministry of National Education (MoNE) have been found.In other words, the lesson study is not a formal model recommended by the MoNE in Turkey.
There are also findings related to PD in lesson study research conducted with English language teachers.For example, lesson study is effective in the easy implementation of the changes made in English curricula by teachers, and it also contributes to their cognitive, social, and emotional development (Zhang, Yuan, & Liao, 2019).In addition, it allows the teachers to observe the classroom from both the perspectives of a researcher and students, enabling them to implement changes in teaching successfully (Tasker, 2014).Teachers interacted to gain new teaching methods and techniques (Purwanti & Hatmanto, 2019).Likewise, peer observation and peer feedback contribute to the PD of English language teachers by supporting the course design (Nami, Marandi, & Sotoudehnama, 2016).
Although studies on lesson study providing PD of English language teachers in Turkey have increased rapidly in recent years, many problems have been pointed out.For instance, teachers implementing the research lesson have difficulty in arranging the lesson hours, preparing the lesson plans (Yüzbaşıoğlu, 2016), and designing the curricular elements (aims, contents, teaching-learning process, and evaluation) appropriately (Orhan, 2020).Moreover, they cannot think independently from the textbooks (Uştuk & Costa, 2021).There are also problems such as lack of administrative support (Bayram & Canaran, 2020), the misconception of the lesson study model (Bayram & Bıkmaz, 2018), and teachers' inability to handle criticism (Karabuğa & İlin, 2019).It seems demanding to implement lesson study effectively in the PD of English language teachers until these problems are resolved.
For the lesson study to be used effectively in the PD of English language teachers, there is a need for further studies on integrating the model into the context in Turkey, beyond putting forward its positive aspects (Bayram & Canaran, 2020).Therefore, it may be helpful to discuss and examine previous studies comprehensively.For seeing beyond the meanings of prior findings, meta-synthesis studies are carried out.A meta-synthesis study conducted to reach a new or improved understanding of the phenomenon under investigation may reveal new insights about the current state of the phenomenon (Paterson, 2012).By comparing the findings obtained from qualitative studies, in-depth and holistic information about the researched phenomenon can be obtained (Gümüş, 2018).Through meta-synthesis, the real reasons behind the difficulties experienced in the lesson study used in the PD of English language teachers can be uncovered, and new solutions that can help the model proliferate can be found.Although the meta-synthesis on lesson study is examined in the international context in Turkey (Serbest, 2014) and mathematics teachers' experiences (Kıncal & Beypınar, 2015), no metasynthesis on English language teachers has been conducted.This study aims to produce a synthesis to proliferate the model by examining the studies on lesson study used as a PD of English language teachers in Turkey.In this context, the following questions were formulated: 1.According to previous qualitative studies, what are the common points about lesson study experiences of English language teachers?2. What is the final synthesis to ensure the proliferation of lesson study as a PD for English language teachers?

Method
The meta-synthesis was adopted to examine the studies on English language teachers' lesson study experiences in the study.Meta-synthesis is defined as the synthesis of findings in qualitative research reports related to a particular topic or focuses for reaching a new or improved understanding of the phenomenon under study (Paterson, 2012;Sandelowski & Barroso, 2007;Thorne, Jensen, Kearney, Noblit, & Sandelowski, 2004).The synthesis produces interpretive results through comparison, integration, and distillation of meanings, concepts, and theories across qualitative studies (Erwin, Brotherson, & Summers, 2011;Finfgeld, 2003;Saini & Shlonsky, 2012;Zimmer, 2006).There are different views on carrying out meta-synthesis (Erwin et al., 2011;Finfgeld, 20003;Howell-Major & Savin-Baden, 2010;Noblit & Hare, 1999;Polat & Ay, 2016;Sandelowski & Barroso, 2007).In this study, the steps (Erwin et al., 2011) followed are: (a) formulating research questions, (b) reviewing the literature, (c) identifying studies to be included, (d) using analysis techniques for meta-synthesis, and (e) presenting the synthesis.Below, these steps are explained in detail.

Formulating Research Questions
It is vital to select the research questions initially to determine how the research is carried out in meta-synthesis (Erwin et al., 2011).The fact that the professional development needs of English language teachers in Turkey cannot be adequately met (Uztosun, 2018) and that numerous problems have been pointed out in the previous lesson study findings show that new solutions are needed.Therefore, research questions were formed for creating a synthesis to proliferate the model in the PD of English language teachers in Turkey.

Reviewing the Literature
After formulating the research questions, a literature review was conducted.In this process, the start date has not been determined, and all studies until June 2021 have been examined.The keywords (see Table 1) were searched in the National Thesis Center of the Council of Higher Education.The databases (EBSCO, Elsevier, ERIC, Mendeley, SCOPUS, Springer, Taylor & Francis, Web of Science) at the Ege University Library, and Google Scholar.First, the keywords related to the lesson study were scanned, then these keywords combined with English language education and English language teachers were searched.The searching process was carried out by both researchers separately, and a total of 111 studies conducted in Turkey were reached.

Identifying Studies to be Included
Identifying studies to be included was carried out in three stages.In the first stage, a table with the title, method, participants, and data collection tools of the studies was prepared.All lesson study research conducted in Turkey was included in the table for not missing any study, and those not relevant to English language education were excluded.In the second stage, the inclusion criteria were determined (Table 2), and after reading the full texts of the remaining studies, the studies not meeting the criteria were excluded.In the third stage, the studies were evaluated in terms of quality.The including process is presented in Figure 1.(Erwin et al., 2011) Studies with a score of 1-10 from the checklist (Erwin et al., 2011) Figure 1.The Process of Including Studies in Meta-synthesis As seen in Figure 1, in the second stage, articles were included first since they were subjected to editorial and reviewer evaluations.In other words, the theses that were converted into articles were excluded.However, since a doctoral thesis (Orhan, 2020) was not converted into an article, it was also included in the research.The studies conducted with pre-service English language teachers (Altınsoy, 2020;Coşkun, 2017;Demirbulak, 2011;Ökmen & Kılıç, 2021;Yalçın Arslan, 2019), systematic analyzes (Uştuk & Çomoğlu, 2019), proceeding reports (Gök, 2016;Songül, Delialioğlu, & Özköse Bıyık, 2018) were excluded.Studies that did not fit the research context were also excluded.One was online lesson study research (Songül, 2019), and the other was conducted with one participant (Karabuğa & İlin, 2020).
In meta-synthesis, a judgment must be made about the quality of each study to be included (Erwin et al., 2011).In the third step, a checklist adapted by Erwin et al. (2011) was used to identify the quality of the studies.The checklist is expected to score according to the indicators of the clarity of the research problem and the purpose of the study, the type of the method, the relevance of the findings, the quality of the discussions, and suggestions.If the score range obtained from the checklist is 11-15, it is classified as good quality, 6-10 as medium quality, and 1-5 as low quality.
Therefore, firstly, the items in the checklist were taken into a table and arranged so that the indicators were put in the row and the studies were put in the column.The studies were then scored independently by the researchers.Finally, the average of the scores was calculated, and seven studies with a score between 11-15 were included.However, an article produced from a doctoral dissertation did not receive the required score.Then the doctoral dissertation of this article was scored, and it was included in the study as it received sufficient points.As a result, a total of eight studies, including six articles and two doctoral theses, were included in the meta-synthesis.Although there is no exact number regarding the sample size of qualitative meta-synthesis, the number varies between 3 and 292 depending on the scope of the subject (Finfgeld, 2003).However, it is generally recommended to include between 8 and 12 studies in the sample (Polat & Ay, 2016).The most crucial variable in determining the sample is the saturation of the coding categories (Finfgeld, 2003).So, the eight samples (studies) in the research might be sufficient for meta-synthesis to provide data saturation as there are 304 codes and 55 categories in them.The main features of studies included in the meta-synthesis are presented in Table 3. Orhan (2020) To examine the social sharing organization activities of English language teachers in the context of lesson study and the changes related to this process.

Single case study
Three English language teachers

Using Analysis Techniques for Meta-synthesis
Different analysis techniques can be used in meta-synthesis studies (Erwin et al., 2011;Sandelowski & Barroso, 2007).This study followed the three-phased process proposed by Howell-Major and Savin-Baden (2010).The first phase is analysis, in which the first-order themes are developed.Firstly, it is necessary to determine the common findings in the studies included in the research (Howell-Major & Savin-Baden, 2010).A data set was created in the Excel file to present and compare the findings of the studies.The names of the researchers who carried out the studies are written in column A, direct quotations of the participants of the studies are added as notes in column B.
Similarly, the comments made by the researchers who conducted the studies as direct quotations were added as notes in column C. The codes and categories found in studies were also written in columns D and E, respectively (Figure 2).Thus, the first-order themes were developed based on the codes and themes in the studies.The second-order themes are obtained in the second phase by aggregating the first-order themes.It involves rereading the first-order themes and integrating similar meanings (Howell-Major & Savin-Baden, 2010).The second-order themes were revealed by constantly comparing the existing codes and categories by reading the studies at different times over four months.In the third phase, the findings of the studies, the first and second-order themes are read repeatedly, and the third-order themes are developed.Moreover, this stage involves critical thinking and inductive analysis, which requires searching for subtexts hidden under the themes and building bridges between themes and concepts (Howell-Major & Savin-Baden, 2010).The synthesis is accomplished by utilizing the bridges established between the findings (Erwin et al., 2011).The final synthesis will be the justifications for the value of the meta-synthesis; therefore, it should be made clear that the synthesis is greater than the parts that compose it (Walsh & Downe, 2005).With the third-order themes developed by the researchers, synthesis has been reached to proliferate the lesson study for PD of English language teachers.The first, second, and third-order themes are presented in Figure 3.

Findings Related to the First Research Question
The findings relating to the standard points about lesson study experiences of English language teachers were gathered under the headings of "the contributions of the lesson study" and "the difficulties in the implementation."

The Contributions of the Lesson Study
The results displayed that there were many contributions to the lesson study.One of the most outstanding contributions of the lesson study is that it offers teachers a collaborative working environment (Bayram & Canaran, 2020).Teachers, who often plan their lessons alone, design research lessons by exchanging ideas with their colleagues.It has been remarked that feedback from colleagues is significant in gaining different perspectives (Karabuğa & İlin, 2019).
Another contribution of the lesson study is that the teachers have the opportunity to experience getting immediate feedback, and they have more focused on student learning (Bayram & Bıkmaz, 2018;Bayram & Canaran, 2019;Karabuğa & İlin, 2019;Yüzbaşıoğlu, 2016).Regarding this result, Teacher 10 expressed: "Lesson study teaches you to step by step to be student-oriented.Through

Insufficient collaboration skills with colleagues
The First-Order Themes The Second-Order Themes The Third-Order Themes (The Synthesis) student observations, interviews, and video recordings, you have solid evidence of what students think about a particular lesson, and you get to understand them better."(Bayram & Canaran, 2020, p. 671).
The observations also enabled teachers to see whether the lesson they designed was working or not (Bayram & Canaran, 2019;Yüzbaşıoğlu, 2016).In addition, the fact that teachers observed from different locations provided a better detection of the problems during the lesson.Thus, teachers could better design the next research lesson (Coşkun, 2017).
Meetings with peers provided teachers to hold a mirror to their teaching (Karabuğa & İlin, 2019).The teachers who previously considered only the content in the textbook instead of the curriculum experienced the lesson plan and material preparation (Uştuk & Costa, 2021).Thus, teachers examined the lessons thoroughly and became reflective (Bayram & Canaran, 2020;Uştuk & Costa, 2021).This positively affected teachers' curriculum development (Orhan, 2020), time management (Bayram & Bıkmaz, 2018), classroom management skills (Karabuğa & İlin, 2019), and motivation (Bayram & Canaran, 2019): Instead of just following the coursebook like a robot, various lessons and alternatives that are content-wise and time-wise realistic could be planned.Probably we could also overcome the timing problem at this institute by lesson study.We have problems covering the schedule because we do not use the time wisely, which was probably the biggest realization about my institution in lesson study.[Oya] (Uştuk & Costa, 2021, p. 10) Lesson study enabled teachers to realize the mistakes they made in the first lesson and correct them in the following course (Coşkun, 2017).For instance, teachers who had difficulty writing goals in the first lesson could express the objectives clearly in the third research lesson (Orhan, 2020).Another example is that while the activities in the first lesson ended late or early as planned, they were completed on time in the following courses (Bayram & Bıkmaz, 2018).Similarly, teachers stated that they improved in the following courses: "The second lesson was better since, after the previous lesson's weaker points, the lesson study group developed the second lesson.Some mistakes made by the first lesson were corrected."[Teacher 1] (Coşkun, 2017, p. 158).The lesson study provided a colleague group giving feedback to help teachers who were left alone with their students in the classroom (Bayram & Bıkmaz, 2018;Karabuğa & İlin, 2019).It becomes a PD opportunity in terms of refreshing the teaching methods and techniques learned during the undergraduate period: I find the lesson study beneficial.These types of studies are kind of professional development.In this way, teachers can learn a lot from each other.Teachers' methodological knowledge is expected to become out-of-date after a certain period, and students' profiles change every year.Therefore, lesson study is an excellent way to improve ourselves professionally.[Teacher 3] (Coşkun, 2017, p. 158) The goal of PD activities is that students learn better and more permanently (Guskey, 2002).In this respect, lesson study allowed teachers to evaluate whether students have learned or not (Bayram & Bıkmaz, 2018).Moreover, it ensured teachers to evaluate their teaching as they take responsibility and participate actively (Karabuğa & İlin, 2019).In other words, teachers were able to identify the strengths and weaknesses of their teaching by reflective thinking: Although I enjoyed the meeting we held today, I also realized what was missing.I saw that I entered the class automatically with the habit and experience of years, but when I had to put planning and application on the subject I was talking about, I saw how stuck I could get.I believe that this study will also develop me professionally.[Seçin Teacher] (Orhan, 2020, p. 181) Unlike the seminar and course model, lesson study provided an opportunity for English language teachers who seek collaborative PD activities (Bayram & Canaran, 2020).Besides, the PD has become from the bottom up, and teachers ignited the fuse of PD (Uştuk & Costa, 2021).Therefore, teachers have started to look warmly to practices that will contribute to their PD: There was an openness to each other.For example, when a teacher comes to our classes and wants to attend my class, I can look more positively now.I would not have reacted before, but now I believe in the necessity of this a little more.I can tell my peer I have a problem with this issue.How do you teach?Can I see?For example, I can say.[Participant 7] (Yüzbaşıoğlu, 2016, p. 139) In the light of these findings, the studies revealed that the lesson study model contributed to English language teachers in extensive ways.It positively affected the teachers' collaboration with their colleagues and their reflective thinking skills.It also provided an opportunity to review their practices in the classroom.Teachers were able to identify the problems in the teaching much more accessible and design student-focused teaching.Hence, teachers who also improved in time management played an active role in student learning, their motivation increased, and their perspectives towards PD changed positively, unlike other PD practices.In this way, teachers experienced a sense of professional refreshment.

The Difficulties in the Implementation of the Lesson Study
Examined studies indicated that there were some difficulties while implementing the model.Teachers not accustomed to a PD model other than the course and seminar did not react positively when the lesson study was introduced.Some teachers were not interested (Uştuk & Costa, 2021), while others intimidated them (Bayram & Canaran, 2019).Additionally, teachers confused the lesson study with other PD practices (Bayram & Canaran, 2020) and misconceptualized the model (Bayram & Bıkmaz, 2018).Therefore, understanding the model also required time: The most challenging aspect was that it was a new concept for me.I did not hear about it before.First, it needed much time and effort to grasp it, be a team member, and design it.
[Teacher 3] ( Karabuğa & İlin, 2019, p. 66) Another difficulty was that the model required prolonged time and effort (Bayram & Bıkmaz, 2018;Bayram & Canaran, 2020;Coşkun, 2017;Karabuğa & İlin, 2019;Orhan, 2020;Yüzbaşıoğlu, 2016).Everything should be planned so that there is no problem in the implementation (Bayram & Canaran, 2019).This situation, combined with the heavy workload, required teachers to give up their free time (Bayram & Bıkmaz, 2018).Hence, teachers complained about this issue: We have got a lot of other duties to fulfill.You know it is not only about teaching for 20 hours a week.You do, maybe, 10 hours of other stuff, which leaves us with insufficient time to do lesson study.[Ayşe] (Bayram & Bıkmaz, 2018, p. 321) The time taken for lesson preparation was overloading the teacher, which negatively affected their perspective to model.(Karabuğa & İlin, 2019).Teachers completing the planning phase in the first research lesson stated that the process became increasingly difficult for the second and third research lessons (Orhan, 2020).Specific points not talked about during the planning phase caused problems in the implementation (Yüzbaşıoğlu, 2016).For example, regarding the completion time of the activities, there were differences between the planned and actual time (Orhan, 2020;Yüzbaşıoğlu, 2016).Therefore, it was hard to find a willing teacher who would make such an effort for a single lesson (Coşkun, 2017), and it did not seem possible for every lesson (Bayram & Canaran, 2020): We analyze an an-hour-long lesson plan and modify it so many times to make it look perfect.I do not think it is worth all the hassle.It is impossible to do the same thing for all the lesson plans we need to teach.So, I do not think lesson study is a sustainable model.[Teacher 13] (Bayram & Canaran, 2020, p. 672) There were difficulties with teachers' meetings, arranging meetings for teachers, and synchronizing the hours of the teachers who teach and observe.There was even a disagreement with the school administration (Yüzbaşıoğlu, 2016): In the simplest term, we had the problem of coming together.Because we all have classes at different times, everyone has a different life personally.That is why we had difficulty finding an ordinary day or time.We also had a hard time finding a convenient environment because we were looking for a quiet place at school where we could focus.There were problems like this.We had trouble arranging the lessons.We tried to coincide with an hour when we were completely free.It has been quite a problem for us as well.[Participant 11] (Yüzbaşıoğlu, 2016, p. 137) In addition, the teachers had difficulties planning the objectives, content, learning experiences, and evaluation (Orhan, 2020) and determining the research problem (Bayram & Bıkmaz, 2018).Therefore, teachers stated that they needed a mentor or a consultant teacher experienced in the model that they could get support from in the process (Bayram & Canaran, 2019).Teacher 1 also expressed their concern by stating: "I guess we should have had a person from whom we could get advice on issues such as finding a research question, data collection tools, and data analysis.Without such support, I have always felt we were doing something wrong."(Bayram & Canaran, 2020, p. 673).
Another problem was that teachers were worried about conducting their lessons before their colleagues (Bayram & Bıkmaz, 2018;Coşkun, 2017).Furthermore, some teachers dominated the meetings and were uncomfortable reporting their criticisms to offend their peers, which stood out as difficulties (Karabuğa & İlin, 2019).
It is sometimes challenging to criticize peers (which is entirely normal because you do not want to offend other teachers).After conducting one of the lessons, I did not receive the feedback I wanted (e.g., some negative points about my teaching).[Teacher 1] ( Karabuğa & İlin, 2019, p. 66) In summary, the findings displayed some difficulties in implementing the lesson study.When the model was first introduced to the teachers, they reacted adversely.Besides, teachers perceived implementations as extra workload, time, and effort may be a first and foremost difficulty in the implementation phase.The teachers' motivation regarding the implementation of the model decreased in time.Another difficulty was experienced in the organization of the meetings and observations.Insufficient support for teachers in planning research and teaching also made it challenging to implement the model.Poor collaborative skills and lack of experience also seemed to cause difficulties in practice.

Synthesis
The answers to the second question are discussed under the headings of "the initiatives at the individual dimension" and "the initiatives at the institutional dimension" (see Figure 3).

The Initiatives at the Individual Dimension
The synthesis of initiatives at the individual level includes the titles of "strengthening the pedagogical design capacity of teachers" and "enhancing the collaboration skills of teachers" for proliferating the lesson study in the PD of English language teachers.

Strengthening the pedagogical design capacity of teachers
The first of the individual initiatives based on the findings is to strengthen the pedagogical design capacity of teachers.The findings displayed that teachers had difficulties in preparing a lesson plan by benefiting from the curriculum (Bayram & Bıkmaz, 2018;Coşkun, 2017;Orhan, 2020;Uştuk & Costa, 2021;Yüzbaşıoğlu, 2016).Moreover, teachers who perceived the textbook as part of a curriculum even stated that taking the book as a basis was a compulsion (Orhan, 2020;Uştuk & Costa, 2021).The teachers realized that they should arrange the lessons according to the interests and needs of the students with the lesson study (Bayram & Bıkmaz, 2018;Bayram & Canaran, 2019;Coşkun, 2017;Karabuğa & İlin, 2019;Yüzbaşıoğlu, 2016).Therefore, all these difficulties point to a problem related to the pedagogical design capacity of teachers.Brown (2009) describes the pedagogical design capacity as a teacher's capacity to use curricular resources consciously to achieve the objectives of the teaching.Curricular resources, defined as "a genre of materials and tools, including, but not limited to textbooks, designed to guide, support, and enhance teaching and learning in schools" (Remillard, 2018, p. 70), act as mediators between teachers and the curriculum.Hence, the teacher-curriculum relationship is interactive; because while the pros and cons of the curriculum affect the teacher, the teacher's perceptions and decisions affect the curriculum (perhaps even change).Brown (2009) expresses this interactive relationship as "perceive" and "mobilize" and defines "a teacher's capacity to perceive and mobilize existing resources in order to craft instructional episodes" as "Pedagogical Design Capacity" (Brown, 2009, p. 29).Using curricular resources is a skill to be developed rather than a simple task (Remillard, 2018), and the pedagogical design capacity allows teaching to be seen as a design activity.The deliberate and conscious use of the curriculum is only possible if the teacher's pedagogical design capacity is robust (Leshota & Adler, 2018).Accordingly, pedagogical design capacity is significant in teaching planning and adaptation skills.
Consequently, it is necessary to strengthen the pedagogical design capacities of teachers to overcome the difficulties they experience during the lesson study.Moreover, a teacher with a solid pedagogical design capacity can carry out instructional design successfully by benefiting from curricular resources consciously (Brown, 2009).Some studies use the "backward design" (Westwood Taylor, 2013) and PD programs based on different teacher roles (Penuel & Gallagher, 2009) to strengthen the pedagogical design capacity of teachers.In addition, some studies present the pedagogical design capacity of teachers (Schipper, Van der Lans, De Vries, Goei, & Van Veen, 2020) and teacher candidates (Beyer & Davis, 2012) developed after lesson study.Teachers who adopt the curriculum (Davis, Beyer, Forbes, & Stevens, 2011) less adhere to the curriculum and more design their lessons (Amador, 2016) have a high pedagogical design capacity.Hence, teachers should be allowed to adapt within the framework of the official curriculum and should be supported by being autonomous in instructional design.
Additionally, in terms of teacher education, pedagogical design capacity can be supported by providing opportunities for teachers to experiment and think about teaching (Knight- Bardsley & Mcneill, 2016).Thus, studies can be conducted to strengthen the pedagogical design capacity of teachers who will participate in the lesson study of English language teachers.For instance, backward design (Wiggins & McTighe, 2007) and understanding by design (Altun & Yurtseven, 2020;Wiggins & McTighe, 2011) for PD activities can lay a solid foundation for the knowledge and skills required in lesson study.Similarly, PD for differentiated instruction (Avcı & Yüksel, 2018;Tomlinson, 2005) may also serve to consider individual differences more in instructional design.Even by integrating these two approaches (Tomlinson & McTighe, 2006), PD, including practical and follow-up studies, can be organized to design lessons, especially by benefitting the curriculum.Consequently, the lesson study model can proliferate with robust pedagogical design capacity teachers.

Enhancing the collaboration skills of teachers
Collaboration between teachers, the basic building block of the lesson study, is a concept that makes the model effective and creates a problem.Therefore, it has been suggested to enhance the collaboration skills of teachers as the second synthesis at the individual dimension.According to the studies, there were some interpersonal disagreements during the lesson study, since teachers had not participated in a collaborative PD activity before (Bayram & Bıkmaz, 2018;Coşkun, 2017;Karabuğa & İlin, 2019;Orhan 2020).This situation displays that teachers should be supported in terms of collaboration skills.Grimsaeth and Hallas (2016) suggest that teachers participating in the lesson study should have a common understanding of collaboration and its results.Additionally, they state that collaboration should be examined in depth in the countries where the model will be implemented since the concept of collaboration is very different in Japan.Perry and Lewis (2009) note that the teachers determining the rules together enable them to reinforce collaboration by perceiving that everyone's opinion was valuable.They also remark that teachers who start working with groups would become experts in collaboration skills over time.Therefore, ensuring teachers work with groups in both pre-service teacher education and PD in Turkey will develop collaboration skills.Lewis (2002) also argues that teachers who isolate themselves from their colleagues and collaborate cannot effectively teach.Thus, teachers should participate in out-of-school activities such as festivals, school trips, and sports competitions to improve this skill.Consequently, if the necessary conditions for enhancing collaboration skills are not provided, it does not seem possible to the lesson study as a commonly used model.

The Initiatives at the Institutional Dimension
The synthesis of initiatives at the institutional level includes the titles of "providing administrator, mentor/facilitator support" and "policy change in teacher education" for proliferating the lesson study in the PD of English language teachers.Providing administrator, mentor/facilitator support In the studies, there are some problems with the administrators in arranging the weekly course schedules of the teachers in a way allowing meetings and observations (Bayram & Bıkmaz, 2018;Bayram & Canaran, 2019;Bayram & Canaran, 2020;Yüzbaşıoğlu, 2016).Similarly, teachers having difficulties also need mentor or facilitator support in the lesson study (Bayram & Bıkmaz, 2018;Bayram & Canaran, 2019;Bayram & Canaran, 2020;Orhan, 2020).Hence, initiatives should provide the administrator, mentor/facilitator support to proliferate the lesson study.Chokshi and Fernandez (2004) state that administrators could support the lesson study by adjusting schedules and providing financial support.The school administrator should also assume the role of a leader, ensure that the model is sustainable, and transfer it to others (Perry & Lewis, 2009).Saito (2012) remarks that the administrators who do not understand the purpose and meaning of the lesson study made negative comments, which discouraged the teachers; however, the administrators understanding the model see the positive aspects of the lesson study and make it familiar in other schools.Therefore, administrators should create a positive synergy for teachers to work collaboratively and be a part of the process when necessary (Muller & Hutinger, 2008).Lee and Madden (2019) emphasized that especially principals must be involved in every step of the lesson analysis.Bieda, Cavanna, and Ji (2015) state that the lesson study is implemented more successfully with the experienced mentor.Mentors can also guide teachers to evaluate and shape the teaching (Chichibu, 2016).
Additionally, facilitator support is valuable as it ensures harmony between the teachers in lesson study (Mynott, 2018).Facilitators can stimulate to reduce teachers' prejudices and reassure teachers concerned about collaboration to participate in the lesson study (Lewis, 2016).Therefore, the administrators need to be supportive, and it is essential to provide mentor or facilitator support for proliferating the lesson study.

Policy change in teacher education
The findings display that the model needs to be included in the education policy for proliferating the lesson study in Turkey; otherwise, teachers would not be willing to do lesson study (Bayram & Bıkmaz, 2018;Bayram & Canaran, 2020;Coşkun, 2017;Yüzbaşıoğlu, 2016).Therefore, lesson study, not practiced much in Turkey apart from academic studies (graduate theses and scientific publications), should be included in education policies starting from national policy documents (strategic plans, vision documents, progress plans).Doig and Groves (2011) state that the teaching profession in Japan is open to peer observation and interpretation, and therefore the lesson study is successful.According to Fujii (2014, p. 3), "lesson study is like air, felt everywhere because it is implemented in everyday school activities".However, the teaching paradigm in Turkey is not like this.In other words, a school system in which teachers observe, give feedback, and criticize each other traditionally does not exist.Hence, a policy change should allow teachers in Turkey to monitor/evaluate their lessons by other teachers and make an instructional design in collaboration.However, another emphasized issue is Japan's determination in education policy.Accordingly, there was no change in the decisions taken about education for at least 20 years (Lewis, 2002).In addition, lesson study is seen as a part of continuous PD in Japan (Murata, 2011).Policymakers also participate in lesson study and change policy per the model in Japan (Lewis & Lee, 2018).
Similarly, Perry and Lewis (2009) remark that the lesson study lasting for four years in a school district in America spread all over the country at the end of the fourth year.Rock and Wilson (2005) state that the budget is taken to cover the experts' costs, hire substitute teachers, and pay the teachers for the reports they prepare, which lead to the initiation of the PD work in their lesson study with the university-school partnership.Maeda and Ono (2019, p. 56) note that schools should adopt "active leadership," They do not stop trying to find solutions to their educational problems.The government should support facilitating the lesson study as an educational innovation.Therefore, for the lesson study to become prevalent in Turkey, the model should be included in medium and long-term strategic plans.The administrative decisions should not be changed frequently, the practices should be monitored, and its continuity should be ensured with moral and material support.In summary, the synthesis we have reached is that initiatives should be made for proliferating the lesson study at the individual and institutional dimensions.We conclude that initiatives at the individual dimension should strengthen the pedagogical design capacity of teachers and enhance teachers' collaboration skills; on the other hand, initiatives at the institutional dimension should provide administrator and mentor/facilitator support and policy change in teacher education.

Discussion, Conclusion, and Implications
The meta-synthesis aimed at proliferating the lesson study used for PD of English language teachers is presented for the first time in this study.Thus, beyond implementing the lesson study identically and expressing its contributions and difficulties, the answer to the question of how the model could be implemented effectively in Turkey must be found (Bayram & Canaran, 2020).In this study, the synthesis has been put forward to see the truth underlying the contributions and difficulties of the model and proliferating the lesson study.
The common findings of the studies reveal the contributions and the difficulties of lesson study for PD of English language teachers.Lesson study enables teachers to be aware of what they do in the teaching process (Dudley, 2014) and to be reflective (Perry & Lewis, 2009) with peer feedback (Lewis et al., 2004).Collaboration with colleagues encourages teachers to benefit from each other in teaching methods and techniques (Purwanti & Hatmanto, 2019).In addition, designing lessons (Elliott, 2019;Takahashi & Yoshida, 2004) positively affects their other PD (Doig & Groves, 2011;Lewis et al., 2004).The common findings of the qualitative research display that the contributions of the lesson study to the teachers confirm the previous studies conducted internationally.
Similarly, the typical findings of the studies are consistent with previous research in terms of the difficulties in implementing the model.For instance, teachers attribute different meanings to lesson study, making it difficult to understand the model (Chokshi & Fernandez, 2004;Fujii, 2014;Zhang et al., 2019).During the implementation of the model, there are problems in bringing teachers together (Müldür & Çevik, 2020).Furthermore, the model requires working in collaboration with colleagues (Boran & Tarım, 2016;Müldür & Çevik, 2020), and teachers shape the teaching differently (Zhang et al., 2019), while more experienced teachers dominate (Zhang et al., 2019), and make the process difficult.Besides, the preparation of the lesson study, entailing a lot of time and effort, has reduced the motivation level of the teachers (Müldür & Çevik, 2020).Similar problems in the literature serve as a hoist in reaching the synthesis and shed light on this research for solving repetitive problems.
For the lesson study to become a prevalent model in Turkey, it is concluded that initiatives should be made both at the individual and institutional dimensions.Teachers' difficulties in preparing a lesson plan, perceiving the textbook as a curriculum, and needing support in designing instruction indicate that their pedagogical design capacities need to be strengthened.It does not seem possible for curriculum to come to life in classrooms unless teachers understand that the curriculum should be based instead on the content of the textbooks (Çetinkaya & Tabak, 2019).Teachers with high pedagogical design capacity know the characteristics of curriculum resources (Remillard, 2018) and can use them consciously (Brown, 2009;Leshota & Adler, 2018).To achieve this, teachers need to put their pedagogical knowledge into practice (Jukic Matić, 2019;Knight-Bardsley & Mcneill, 2016), adapt the curriculum (Davis et al., 2011), and know how to use curriculum resources (Amador, 2016).Moreover, PD for backward design (Westwood Taylor, 2013;Wiggins & McTighe, 2007), understanding-by design (Altun & Yurtseven, 2020;Wiggins & McTighe, 2011), and differentiated instruction (Avcı & Yüksel, 2018;Tomlinson, 2005) can pave the way for strengthening the pedagogical design capacity.Blending these PDs (Tomlinson & McTighe, 2006) can also be helpful.
Another initiative at the individual dimension is to enhance the collaboration skills of teachers.Although collaborative PD activities are the most effective way in the PD of teachers, collaborative activities remain at 21% in Turkey (OECD, 2019) is quite thought-provoking.Similarly, teacher observation and feedback play a key role in teacher collaboration; however, 59% of teachers in Turkey have never done such a practice before (OECD, 2020).Emphasizing that collaboration is significant in PD, Darling-Hammond, Hyler, and Gardner (2017) stress that every school can implement collaborative practices in its way.Hence, steps should be taken to support teacher participation in collaborative PD activities in their schools.Finally, it is suggested that there should be positive interdependence among teachers.Each teacher should be evaluated individually to support teachers in working collaboratively to internalize and apply the new knowledge in the long term (Johnson & Johnson, 2017).
In initiatives at the institutional dimension, on the other hand, the support of administrator, mentor/facilitator, and a policy change in teacher education is needed for proliferating the lesson study.The organization of non-teaching times, the existence of a "Research Steering Committee" in each school, the annual meetings held with the groups, and the rooms allocated to the teachers for lesson study, a routine in Japanese education, have been the facilitators of the model (Lewis & Takahashi, 2013).Administrator support is fundamental for teachers to participate in PD, and it is difficult for PD activities not supported by administrators to be successful (Eroğlu & Donmuş Kaya, 2021;İlğan, 2013).Therefore, administrators should motivate teachers sufficiently to ensure their PD (Aydın et al., 2021;Gözler & Özmen, 2008).Furthermore, in research conducted by the OECD (2019), administrators state that mentoring is essential in the performance of teachers and students.However, only 15% of newly qualified teachers (1-5 years) in Turkey have mentors (OECD, 2019).In this respect, administrators bridge the gap between teachers wanting to be a mentor and teachers needing mentor support.Expressing mentoring as a part of PD, Hudson (2013) asserts that mentors can guide teachers about teaching methods, techniques, and materials.Mentors can help teachers with the subjects they need, and thus improvement can be achieved in teaching (Onchwari & Keengwe, 2008).So, a facilitator in teacher workgroups provides their PD by presenting their knowledge and skills to the group (Sierra Piedrahita, 2007).Becuwe, Tondeur, Pareja Roblin, Thys, and Castelein (2016) also highlight that a facilitator can support teacher groups in paperwork, communication by structuring the process and collaborating with teachers.
Furthermore, the national education policy should include the lesson study model.No PD activity becomes permanent without government policy (Abazoğlu, 2014).Seleznyov, Goei, and Ehren (2021) warn that if the lesson study, as a borrowed policy, is not handled carefully, local stakeholders may show considerable resistance, and the model may have limited longevity.Therefore, there is a need for a long-term (Lewis, 2002;Perry & Lewis, 2009) teacher education policy allowing peer observation (Doig & Groves, 2011) and accepting lesson study as an extension of PD (Murata, 2011).Consequently, there can be initiatives to develop collaboration skills in pre-service teacher education.Furthermore, it is beneficial to consider covering the costs of the participants and giving additional payments (Rock & Wilson, 2005).
It can be considered a limitation that this study only covers lesson study research conducted with English language teachers in Turkey.Therefore, it may be valuable to examine studies implemented internationally or with teachers from different branches in future meta-synthesis.In addition, how the pedagogical design capacity of teachers affects the performance in the lesson study can be examined.Similarly, how teachers perceive collaboration skills and reflect on the lesson study can be discussed.What is more, how administrators impact lesson study might be examined in Turkey?Several findings from international lesson study research display there are generally significant adaptations of the model when applied in countries other than Japan (Seleznyov et al., 2021).For example, the Research Lesson Study in the UK (Dudley, 2013), the Collaborative Lesson Research in the USA (Takahashi & McDougal, 2016), the Learning Study in Hong Kong and Sweden (Holmqvist Olander & Nyberg, 2014), and the Chinese lesson study (Huang, Fang, & Chen, 2017) are among these adaptations.In order to develop the Turkish lesson study model (Turkish adaptation), long-term research should be carried out in different courses and grade levels through research projects supported by TUBITAK.In other words, it is valuable to examine how the model can be adapted to Turkey's educational-cultural context, teacher autonomy, and identity.Research that will expand the synthesis presented in this study can guide the adaptation of the model within the Turkish educational context, while the initiatives to proliferate the lesson study in the PD of teachers can gain momentum.

Figure 2 .
Figure 2. Developing the First-Order Themes

Figure 3 .
Figure 3.The First, Second, and Third-Order Themes

Table 3 .
Main Features of the Studies Included in the Research