Copyright © The Author(s) Vol. 3, No. 1, January 2022 e-ISSN: 2723-4126 p-ISSN: 2776-8880 55 A DECADE OF RESEARCHING ON PROFESSIONAL DEVELOPMENT IN A GRADUATE PROGRAM A SYSTEMATIC REVIEW Le Xuan Mai1*, Le Thanh Thao2 1,2 Can Tho University, Can Tho, Vietnam lxmai@ctu.edu.vn ABSTRACT This paper aims to provide a logical and comprehensive systematic review of MA students’ theses related to professional development (PD) in an educational institution in the Mekong Delta of Vietnam. This systematic review used a qualitative method to analyze 28 unpublished PD theses (2010 – 2020) in a graduate program of a public tertiary institution in the Mekong Delta, Vietnam. There were four main research concerns, including (1) research aims, (2) research methodology, (3) findings, and (4) limitations of the theses. After the review, a list of strengths and weaknesses of these studies is found, evaluated, and presented in this article. The review shows that these studies did contribute diverse knowledge and practices of PD in the educational system of Vietnam, particularly in the Mekong Delta. On the other hand, the data collection instruments and research designs needed improvement to a certain extent. Specifically, observations were not used much in the theses. Besides, the candidate researchers overused a descriptive research design for their theses. Thanks to the analysis, some implications and new ideas for further research in PD are discussed at the end of this paper. Keywords: EFL Teachers, Master Theses, Mekong Delta, Professional Development, Systematic Review INTRODUCTION First and foremost, English has become obligatory in many Asian countries, including Vietnam. English plays the role as the working language of the Association of Southeast Asian Nations (ASEAN) nations to support this group to interact efficiently and get more possibilities to cooperate with the more cosmopolitan global ones (ASEAN Secretariat, 2009). However, most of them have not had sufficient resources or high-quality EFL teachers. As a result, professional development (PD) in English teaching and learning has gotten much attention from Vietnam educators. The conceptualizations of PD have been explored in-depth and width by researchers from all corners of the world (e.g., Friend & Cook, 1992; Hargreaves & Fullan, 1992; Guskey, 2000; Bailey, 2001; and so on). In brief, teacher PD are those activities enabling them to enhance pedagogical knowledge and empower them to help promote their students’ achievements in learning. Along with the history of research in this field, many PD activities enhancing teachers’ professionals have http://u.lipi.go.id/1593190689 http://u.lipi.go.id/1593190689 mailto:lxmai@ctu.edu.vn Copyright © The Author(s) Vol. 3, No. 1, January 2022 e-ISSN: 2723-4126 p-ISSN: 2776-8880 56 been explored in previous articles (e.g., Ganser, 2000; Guskey, 2000; Garet et al., 2001; Villegas-Reimers, 2003; Boyle et al., 2004; Diaz-Maggioli, 2004; Richards & Farrell, 2005; Murray, 2010; and so on). Based on these studies, there are six main groups of PD activities, namely (1) training/ qualification programs, (2) observations, (3) collaborations/ interactions, (4) scientific work, (5) reflective teaching, and (6) participating in workshops and conferences. However, many factors hinder the impact of PD activities, such as lack of funding (Smith & Gillespie, 2007), limited-time (Darling-Hammond, 1999), daily activities (Cochran-Smith, 2004), teachers’ hesitance of failure and avoidance to get much attention (Duke, 2004), and a few others. As observed in these studies, both internal and external factors can affect the impact of teachers’ PD on their teaching practices. In the Vietnamese context, many reforms in curriculum design, development, revision, and review have been made by the Ministry of Education and Training (MOET) to help EFL teachers develop their teaching (Le et al., 2019). Notwithstanding, the proactive government interruption based on the one-size-fits-all approach faced a counterproductive effect that Vietnamese EFL teachers were unable to catch up with the changes and neglected to meet the expectations of their superiors (Le et al., 2019; Author, 2020). Less qualified teachers who are struggling with changes need to have chances to develop their professionals. Furthermore, it seemed to be formidable when the Vietnamese government approved Vietnam’s National Foreign Languages 2020 Project (NFLP 2020) with a fund of millions of dollars to heighten the number of opportunities for Vietnamese people in the universal race (Le et al., 2019). Many English language teaching (ELT) pedagogical reforms were offered in this project, such as teaching English as a mandatory subject in the school curriculum, employing either untrained or partially trained English native speakers as EFL teachers, increasing instructional ampere-hours, using new textbooks, applying the learner-centred task-based method, or maximizing learners’ exposure to English in-and-outside of the classrooms. However, after the intervention, the results of English in the annual national graduation examination of Vietnamese high school students are still far from the expectations and teachers’ competence is the foremost reason for these setbacks (Le et al., 2019). Consequently, numerous studies have been conducted to explore the impact of professional development (PD) on EFL teaching and learning. Remarkably, the researched institution has been consistently encouraging their students, bachelors, masters, or doctorates, to conduct their research for their graduation theses in this field. In respect of this dedication, PD has been understood at a certain level. However, after a decade of learning about this field, some shortcomings were explored as duplicated topics, unbalanced research designs, lack of in-depth investigations of current issues, and so on. Consequently, the findings of these theses seem to be not as significant well as expected. Related to the abovementioned issues, this systematic review addressed four main research concerns, including (1) research aims, (2) research methodology, (3) findings, and (4) limitations of the theses. Consistently, the review addressed four main research questions: 1. In the theses, what did the candidate researchers aimed to investigate? 2. How did the candidate researchers design their theses? 3. What did the candidate research find in their theses? http://u.lipi.go.id/1593190689 http://u.lipi.go.id/1593190689 Copyright © The Author(s) Vol. 3, No. 1, January 2022 e-ISSN: 2723-4126 p-ISSN: 2776-8880 57 4. What limitations could be observed in the theses? METHODS A qualitative method was used to conduct this review on 28 unpublished PD theses in a graduate program of a public tertiary institution in the Mekong Delta, Vietnam. The analysis was conducted according to the following themes: research topics, research objectives, research designs, frameworks, research instruments, participants, research contexts, key results, and research limitations. From the theses review, the reviewers discussed and suggested comprehensive ideas for further investigations. These MA theses were conducted on EFL teachers’ PD in a decade (2010-2020). They were selected according to these criteria: (1) they are currently stored in the main library of the institution and have e-versions, or (2) the theses were supervised by one of the researchers. The researchers made a list of all the theses and then read through them to note down and comment on the information. The notes and comments were made according to the content of the main parts of theses. There are twenty-eight theses about the PD research area. They were written between 2010 and 2020. The number of theses in each year is summarized in Table 1. Table 1. Summary of theses information reviewed, 2010 – 2020 Year Number of theses 2020 3.00 2019 8.00 2018 3.00 2017 2.00 2016 3.00 2015 1.00 2014 - 2013 3.00 2012 3.00 2011 - 2010 2.00 Total 28.00 Except for 2011 and 2014, PD was selected as the field that graduate students in the program desire to learn about. Significantly, eight theses about PD were conducted in 2019. Related to this year, throughout educational legislation, the Vietnamese government removed lifelong payroll for teachers. As a result, Vietnamese teachers need to develop their profession, or they can be eliminated by the external or objective selection in which the better will survive, and the worse will be left. It is inferred as one of the reasons for the highest number of research in relevance with PD in 2019. On the other hand, the projects of textbook renewal in 2011 and changes from summative assessment to formative one in 2014 might distract the graduate students’ attention to PD issues. http://u.lipi.go.id/1593190689 http://u.lipi.go.id/1593190689 Copyright © The Author(s) Vol. 3, No. 1, January 2022 e-ISSN: 2723-4126 p-ISSN: 2776-8880 58 The researched institution is located in a central city in the Mekong Delta in Southwest Vietnam. Those who do not know about the Mekong Delta are known as the Western Region of the South or South-Western Region in Vietnam. This region comprises Can Tho as a central city in the South of Vietnam and twelve other provinces, namely Long An, Tien Giang, Ben Tre, Vinh Long, Tra Vinh, Hau Giang, Soc Trang, Dong Thap, An Giang, Kien Giang, Bac Lieu, and Ca Mau. In Vietnam, the Mekong Delta is considered a “low-land” in education; as a result, it becomes a potential research site to explore the issues related to PD for teachers with the hope that students’ academic performance and competence will be enhanced. The analysis procedures followed the following steps. First, the researchers used an online management system containing the theses provided by the institution in order to read the theses related to PD. Then, the researchers created a table including five columns, namely title, year, aims, methodology, findings, and limitations. After that, the researchers read through the theses and summarized the necessary information for the review in the above- mentioned table. Finally, the researchers cross-checked and compared the summaries. The similarities would be kept, but the differences would be rechecked and debated for making decisions between keeping or deleting. RESULTS Research Aims Compared to the proposed frameworks, despite an unequal number of theses, they have covered all issues in PD activities. Table 2 displays the summary of investigated themes according to PD activities. Table 2. Summary of investigated themes according to PD activities PD activities Number of theses General views 10.00 Collaborations/ interactions 5.00 Observations 4.00 Reflective teaching 4.00 Inquiry/ action research 3.00 Mentoring/ coaching 1.00 Workshops/ conferences 1.00 Total 28.00 Among 28 theses, ten of them did not focus on a particular PD genre (N=10). In terms of theses on a specific type of PD activities, the most concerning topics related to PD activities are collaborations/ interactions (N=5), observations (N=4), reflective teaching (N=4), and inquiry/action research (N=3). On the other hand, although the topics including peer mentoring/ coaching (N=1) and attending workshops and conferences (N=1) have been examined, at an inadequate level. Related to specific concerns of the researched papers, none of them focused on a particular issue. It could enrich the findings on PD issues in general; however, the reviewing http://u.lipi.go.id/1593190689 http://u.lipi.go.id/1593190689 Copyright © The Author(s) Vol. 3, No. 1, January 2022 e-ISSN: 2723-4126 p-ISSN: 2776-8880 59 process showed that these theses did not investigate an in-depth understanding of the impact of specific PD activities on EFL teaching and learning in Vietnam. Table 3 illustrates the summary of researched themes according particular interests of MA students. Table 3: Summary of researched themes according to particular issues Researched themes Number of theses Impact and factors 14.00 Impact and suggestions 4.00 Expectation and satisfaction 3.00 Impact and satisfaction 3.00 Satisfaction and suggestion 2.00 Impact and expectation 2.00 Total 28.00 Specifically, the combination of the impact of and factors affecting PD in teaching practice was well-investigated (N=14). Other combinations did not attract the researchers at that high level. Specifically, they included impacts of and suggestions for other PD (N=4), expectations of and satisfaction with PD (N=3), the impact of PD and satisfactions with PD (N=3), satisfactions with and suggestions for other PD (N=2), and impact and expectations of PD (N=2). Besides, it is effortless to figure out that the researchers were interested in the impact of PD on teaching and learning practice the most (N=23). On the other side, participants’ satisfaction with PD (N=8), suggestions for other PD (N=6), and expectations of PD activities (N=5) are not received much attention from the researchers. METHODS Participants The reviewed theses focused on investigating EFL teachers’ perceptions of PD rather than other stakeholders in terms of participants. The summary of participant information is summarized in Table 4. Table 4. Participant information Participants Number of theses K12 teachers 16.00 High education lecturers 4.00 Private language centre teachers 4.00 Novice teachers 3.00 School administrators 1.00 Total 28.00 Specifically, K12 teachers were paid attention to the most (N=16), followed by higher education lecturers (N=4), private language centered teachers (N=4), and novice teachers http://u.lipi.go.id/1593190689 http://u.lipi.go.id/1593190689 Copyright © The Author(s) Vol. 3, No. 1, January 2022 e-ISSN: 2723-4126 p-ISSN: 2776-8880 60 (N=3). Another one conducted their study to investigate administrators’ perceptions (N=1). Other stakeholders’ ideas were not observed in these theses (N=0). Research Contexts What was observed is that not all cities or provinces were selected as the research sites by the MA students of this educational institution a decade ago. Table 5 summarizes the research contexts in the theses. Table 5. Summary of research contexts Research context Number of theses Can Tho City 11.00 Ca Mau Province 2.00 Soc Trang Province 2.00 Ben Tre Province 2.00 Vinh Long Province 2.00 Tien Giang Province 1.00 Kien Giang Province 1.00 Bac Lieu Province 1.00 No specific context 6.00 Total 28.00 Specifically, Can Tho city is the most concerned venue (N=11), followed by the provinces such as Ca Mau (N=2), Soc Trang (N=2), Ben Tre (N=2), Vinh Long (N=2), Tien Giang (N=1), Kien Giang (N=1), and Bac Lieu (N=1). Meanwhile, the other provinces as An Giang, Dong Thap, Tra Vinh, and Long An, were not significantly paid adequate attention to (N=0). Besides, some theses collected data from EFL teachers in general, not those working in a specific city or province (N=6). Research Designs Research designs in these theses were analyzed to state that almost all studies were conducted as a descriptive research design (N=27), and only one study was administered as a case study (N=1). The others, such as action research, casual design, cohort design, cross- sectional design, experimental design, exploratory design, historical design, longitudinal design, observational design, philosophical design, and sequential design, were not used. Data Collection Instruments Besides the research designs, data collection instruments also differ studies from each other. The summary of data collection instruments is illustrated in Table 6. Table 6. Summary of data collection instruments Instruments Number of theses Questionnaire only 1.00 http://u.lipi.go.id/1593190689 http://u.lipi.go.id/1593190689 Copyright © The Author(s) Vol. 3, No. 1, January 2022 e-ISSN: 2723-4126 p-ISSN: 2776-8880 61 Questionnaire and interview 21.00 Questionnaire, interview, and content analysis 3.00 Interview, content analysis, and observation 1.00 Questionnaire, interview, and observation 1.00 Interview and content analysis 1.00 Total 28.00 Most of the studies used mixed-method approaches to collect data, except a study using a single questionnaire (N=1). Specifically, the most used mixture is the combination of questionnaires and interviews (N=21), followed by the combination of three different instruments, questionnaires, interviews, and content analysis (N=3), the combination of trios, including interviews, content analysis, and classroom observations (N=1), the combination of interviews and content analysis (N=1), and the combination of questionnaires, interviews, and classroom observations (N=1). Prominent Findings in the Theses Related to the contributions of the previous studies to the literature, their prominent findings are divided into four main categories, including the impact of existing PD on teaching practice, participants’ satisfactions with PD, their expectations from PD, and factors hindering PD. First, PD activities bring many benefits to EFL teachers. Specifically, PD activities help them perform well in the classrooms and bring better students’ learning outcomes (N=5); broaden academic and pedagogical knowledge (N=4); understand teaching values, classroom and students (N=3); establish a trusting relationship with colleagues (N=3); improve teachers’ professional identities related to developing English teaching competences (N=3); enhance cooperation and interaction between students and teachers (N=2); change the teaching beliefs, use the materials and apply technology more effectively (N=1); understand more about high school contexts, and adjust pedagogical behaviours (N=1); realize their colleagues’ strengths, increase staff relationships, and improve communicative skills (N=1); increase students’ engagement, and motivate students’ self- study (N=1); and be more self-confident, determine self-efficacy (N=1). Second, despite many beneficial features that PD brings to teachers’ teaching practice, some studies found that teachers were not satisfied with the PD activities they used to have. Compared to the mentioned reasons above, some reviewed theses showed that EFL teachers were satisfied with their trainers (N=4). However, another remarkable finding in the reviewed theses stated that some PD activities were not practical (N=3). Third, to meet teachers’ expectations, understanding their needs or expectations is essential. Here are some teachers’ expectations that they want to gain after participating in PD activities: developing instructional strategies, teaching skills, and academic knowledge (N=5); planning practical lessons, creating a meaningful and supportive learning environment, designing practical assignments and activities (N=3); developing technology for teaching (N=3); organizing workshops taken place in their province in summer by qualified university teachers as trainers (N=2); acknowledging additional testing and http://u.lipi.go.id/1593190689 http://u.lipi.go.id/1593190689 Copyright © The Author(s) Vol. 3, No. 1, January 2022 e-ISSN: 2723-4126 p-ISSN: 2776-8880 62 assessment types, syllabus design, ICT, and classroom management (N=2); gaining a deep understanding of learners (N=1); and promoting resource adaptation and selection and having training courses (N=1). Finally, many factors hindering PD have been found in the reviewed theses. However, time constraints, excessive workload (N=8), and lack of institutional support (N=5) were highly prominent. Common Limitations The most common limitation of the previous MA theses related to PD in this institution was small samples. Two possible explanations were provided for this limitation. First, the MA students, researchers of the previous studies, did not have sufficient financial and political power to enlarge their research samples. The other possible explanation is that these MA students did not fully understand the concept of a small sample, so they just mentioned it as one of the limitations. Additionally, most authors agreed that it was disappointed to conduct their studies without using observations or other instruments for the data collection. An empathetic response has been made to explain this limitation that the researchers might not have enough time to conduct observations. DISCUSSION The number of theses that did not focus on one type of PD is overwhelming compared to those investigating each category separately. It has helped provide a general picture of PD in the region; however, the picture just covered the surface of the issue, not in-depth understanding. Besides, this also proved that Vietnamese educators had been confused about which type of PD activities can foster EFL teaching in practice the most; as a result, research on PD is just in a repetitive cycle. K12 teachers were overpaid attention to by these theses. On the other hand, the PD of Vietnamese teachers for higher education and private language centres, novice teachers, or educational administrators was not understood clearly because of the lack of investigations. Furthermore, other stakeholders, consisting of parents, media, community representatives, students, and so on, have not had chances to raise their voices yet. The findings did not align with Leisyte and Westerheijden's (2014) beliefs, who indicated that all stakeholders play their specific and essential roles in teaching and learning development. Therefore, without their perspectives, understanding the PD issues in these reviewed theses seemed to be unfulfilled. Understandably, the researchers paid much attention to the impact of PD on teaching and learning practice because it is the best way to measure PD's effect. Regarding these measurements, the impact of PD has been well-explained in the Vietnamese educational context. However, other issues, including EFL teachers’ satisfactions, suggestions, or expectations, also play a remarkable role in increasing the quality of PD activities. As explained by Guskey (2002), evaluation is an intentional process to collect and analyse the information through appropriate methods and techniques to determine its value. Besides, Timmermans et al. (2016) added that the measurements of teachers’ expectations of a http://u.lipi.go.id/1593190689 http://u.lipi.go.id/1593190689 Copyright © The Author(s) Vol. 3, No. 1, January 2022 e-ISSN: 2723-4126 p-ISSN: 2776-8880 63 particular PD activity also prove its value on their teaching in practice. Otherwise, more research is needed on the impact or effects of particular PD activities such as reflective teaching, action research, attending conferences, the community of practice, and classroom observations. The PD issues in a particular city, such as Can Tho, could be well-studied within itself. On the other hand, these issues in the other provinces have been little researched. Therefore, it lacks a comparison among PD activities implemented in different places. Besides, six reviewed theses collected data from the teachers working in the Mekong Delta in general, but the sample size could not generalize their results. To ensure the reliability of results in a study, the sample should satisfy the criteria for the sampling technique proposed by Parel et al. (1973). As a result, the understanding of PD in this region is not as depth as expected. According to Anastas (1999), although descriptive studies can collect a large amount of data for analysis in detail, the results from a descriptive study cannot answer a hypothesis thoroughly or convincingly. Therefore, the reviewed theses might provide a potential number of participants to draw a general view of PD in the Mekong Delta. However, the results should be rechecked by employing other types of research design. While quantitative data from the questionnaires provide information on a large sample and yields results on frequency and magnitude of trends, qualitative data from the interviews offer insightful perspectives on the research topics and explain the issues in detail. However, to measure the impact of PD on teaching and learning in practice, the results from those instruments seemed to be unconvincing. For example, as stated in Eddy et al. (2015), the classroom observation tools can identify implementing elements that have been shown to increase student outcomes related to achievement, logic development, or other relevant learning goals. Moreover, the tool can clarify the research-supported elements of best practices for classroom interactions in practice. The most prominent findings were that PD activities help improve teaching performance, professional knowledge, and students’ learning outcomes. In general, the findings related to the impacts of PD found in those theses were in line with several previous studies (e.g., Buczynski & Hansen, 2010; Piasta et al., 2012; Earley & Porritt, 2014; and so on). Besides, the findings regarding teachers’ satisfactions with PD were aligned with Bayar and Kösterelioğlu (2014), who listed five main reasons for teachers’ low satisfaction with PD, namely offering only traditional PD activities, not involving teachers in the design of PD activities, ignoring teachers’ needs during the process of planning of PD activities, offering activities unrelated to authentic classroom situations, and having low quality of instructors in PD activities. Additionally, attested as a more complicated role rather than an effective teacher, teacher educator has to categorize for affective needs, coach a large number of participants, interpret unexpected situations and provide appropriate feedback, point out particular needs of trainees, and so on (O’Dwyer & Atli, 2015). Then, it was indicated as a reason failing PD in the study by Helterbran and Fennimore (2004) which asserted that PD sometimes was irrelevant, ineffective, and unrelated to participants’ needs. In terms of institutional support, it is in line with Opfer and Pedder (2011), who found that the absence of institutional supports strongly decreased EFL teachers’ willingness to http://u.lipi.go.id/1593190689 http://u.lipi.go.id/1593190689 Copyright © The Author(s) Vol. 3, No. 1, January 2022 e-ISSN: 2723-4126 p-ISSN: 2776-8880 64 participate in PD. Regarding time constraints and excessive workload, teachers in the study by Teig et al. (2019) complain that time constraints from the excessive workload and social life had prevented them from implementing cognitive-activation strategies to enhance their self-efficacy, although they strongly believed in the values of those strategies. CONCLUSION Research aims of the theses have been well-achieved. The researchers of the theses explored most of the themes efficiently even though they did not much provide in-depth understanding of the issues. In the general terms, the theses completed their missions answering the research questions. Therefore, the literature in the field has been strongly enriched thanks to the remarkable efforts of the researchers. In terms of research design, the unbalance is shown. Remarkably, most theses focused on descriptive research rather than experimental research. Previous research has shown that EFL teachers’ perceptions of PD can be significantly different from how they practice in real classrooms. Then, regarding the participants, most theses investigated K12 EFL teachers, rather than EFL lecturers in tertiary education or those at vocational institutions, and among K12 teachers, few were teaching at primary schools. Also, most of these theses studied the teachers rather than the administrators, PD organizers or coordinators, PD trainers, and other stakeholders. As a result, potential graduate students and researchers can focus on these categories of participants. Additionally, researchers are emboldened to invite teachers working in private language centres and freelancers or novices to partake in their studies. Regarding research contexts, the sample should be chosen in those provinces without any previous investigation, such as An Giang, Dong Thap, Tra Vinh, and Long An. These research sites may provide more significant findings in order to enhance the PD quality in Vietnam. Related to data collection instruments, it is undeniable that questionnaires and interviews, mainly semi-structured interviews or the like, are extremely useful to collect data to understand human beings. Nonetheless, they have been overused. After reviewing the MA theses towards PD in this tertiary institution in the Mekong Delta, Vietnam, for ten years (2010-2020), some strengths and weaknesses were found. In general, twenty-eight theses are not an impressive quantity. Much evidence shows how PD is necessary for an educational system; therefore, it is difficult to determine that Vietnamese EFL teachers are much concerned about PD. Nevertheless, all of them have shown a sufficient augmentation to promoting PD in practice. Regarding the findings of the theses, they have contributed to the development of literature on PD activities in Vietnam. Moreover, they provided informative data for school administrators worldwide on how they can meet EFL teachers’ demands or avoid the hindering factors for PD, especially institution supports. There are three remarkable common limitations found in the theses, including small n- size, time constraints, and lacking the use of appropriate collecting data instruments. Because of the mentioned above limitations, the theses just explored the issues on the surface, not in-depth understanding. In short, the candidate researchers significantly contributed to the enrichment of the field. Most of the theses profoundly found interesting and useful results for enhancing the quality of PD events in the Vietnamese context. However, there was space for them to http://u.lipi.go.id/1593190689 http://u.lipi.go.id/1593190689 Copyright © The Author(s) Vol. 3, No. 1, January 2022 e-ISSN: 2723-4126 p-ISSN: 2776-8880 65 improve. For instance, research design, collecting data instruments, and research sites should be taken into careful considerations. IMPLICATIONS Overusing descriptive research design leads to a doubt whether PD training in Vietnam has a significant impact on teachers’ practice. To find the answer, no other choice except to conduct more classroom observations with good checklists. Therefore, future theses can experiment and report the effects of PD programs or activities on EFL teachers. Besides, Prediger et al. (2019) also proposed three interesting strategies for setting research agendas dealing with the multi-level structure of PD activities, including lifting strategy, nesting strategy, and unpacking strategy. Researchers interested in conducting PD studies can use these three practical strategies to employ their work. The diversity of types participants who play different roles in EFL teaching and learning in the theses drew a general picture of PD in the Southwest of Vietnam. One more idea is that English-native speakers or second language speakers should be selected as participants for further research in the Vietnam context. Additionally, it could be fascinating to differentiate teachers’ responses to PD in separate research sites that were not obvious in the previous studies. If possible, other parts of Vietnam should be elected as the research site for the comparison. The differences between the North and the South of Vietnam in terms of education may exist. In this knowledge economy era, it could be worthy of checking which area has trained the human resources better throughout the quality of PD training. Moreover, for PD investigations in the future, more data collection methods should be utilized. For example, observations should be used to research the impact of PD on teaching practices. Instead of only semi-structured interviews, focus group interviews can also be employed. Also, researchers should use more research methods to collect data related to content and documents like journals and official document analysis. Despite these significant benefits, potential ideas and directions for future research are suggested as follows. In terms of PD research topics, future PD theses can be administered to investigate the impact of specific PD activities, such as training or attending workshops and conferences, the community of practice, reflective journals, and the like, on teachers’ professional growth. Also, more research should investigate the follow-up activities that the teachers implement after their training programs. Moreover, just a few studies on teachers’ satisfaction or evaluation of PD activities were conducted. Notwithstanding, without shortcoming recognitions, the quality of PD activities seems to be far from expectations. It has indirectly explained the learning outcomes of Vietnamese students, which were unsatisfactory. Therefore, administering more studies to investigate all issues surrounding PD is essential to produce more qualified teachers and meet the expectations of the Vietnamese government. For the deficiencies admitted by the MA scholars, to solve the problem of small sample size, it is crucial to help promote their power through addressing cover letters to research sites, establishing a partnership with other institutions to expand the research objects, or making a tight connection with MOET to accommodate researchers sufficient support. In http://u.lipi.go.id/1593190689 http://u.lipi.go.id/1593190689 Copyright © The Author(s) Vol. 3, No. 1, January 2022 e-ISSN: 2723-4126 p-ISSN: 2776-8880 66 another assumption, researchers were not aware of what a small sample is. As a piece of evidence, none of them cited a framework for a small sample. To help beginning researchers, the research team introduced Parel et al. (1973) to advise them on ways of determining sample size. Besides the sample size issue, MA students also face trouble with the time constraints for the motive of accompanying observations in their studies. According to Zohrabi (2013), despite the many benefits that observations can make, an observational process takes a tremendous amount of time. Accordingly, researchers should not be under high pressure of on-time submission. This theses review hopes to provide readers helpful literature and inputs for their future research in the Mekong Delta contexts. This review summarizes what has been done in the field of EFL teachers’ PD by graduate students in the Mekong Delta between 2010 and 2020. It also includes suggestions and recommendations for future research in the field. The reviewers look forward to more new research, thanks to their work. ACKNOWLEDGEMENT Thanks to all researchers who are the authors of the twenty-eight reviewed papers. These studies have significantly contributed to enhancing the quality of PD training in Vietnam and worldwide. Furthermore, without the support of these researchers, the writers were not able to finish their work and proposed this valuable review to people who need. Hopefully, this article can be published in a reliable publication to spread its impact. REFERENCES Anastas, J. (2000). Research Design for Social Work and the Human Services. Columbia University Press. ASEAN Secretariat. (2009). ASEAN Socio-Cultural Community Blueprint. Jakarta: Author. Author (2020) Bailey, K. M. (2001). Twenty Questions about Action Research. PASAA: A Journal of Language Teaching and Learning in Thailand, 32, 1-18. Bayar, A. & Kösterelioğlu, İ. (2014). Satisfaction Levels of Teachers in Professional Development Activities in Turkey. Turkish Studies, 9(2), 321-333. Boyle, B., While, D., & Boyle, T. (2004). A Longitudinal Study of Teacher Change: What Makes Professional Development Effective?. Curriculum Journal, 15(1), 45-68. Buczynski, S., & Hansen, C. B. (2010). Impact of Professional Development on Teacher Practice: Uncovering Connections. Teaching and Teacher Education, 26(3), 599-607. Cochran-Smith, M. (2004). The Problem of Teacher Education. Journal of Teacher Education, 55(4), 295-300. Darling-Hammond, L. (1999). Target Time Toward Teachers. Journal of Staff Development, 20(2), 31-36. Duke, D. L. (2004). The Challenges of Educational Change. Allyn & Bacon. http://u.lipi.go.id/1593190689 http://u.lipi.go.id/1593190689 Copyright © The Author(s) Vol. 3, No. 1, January 2022 e-ISSN: 2723-4126 p-ISSN: 2776-8880 67 Earley, P., & Porritt, V. (2014). Evaluating the Impact of Professional Development: The Need for a Student-Focused Approach. Professional Development in Education, 40(1), 112- 129. Eddy, S. L., Converse, M., & Wenderoth, M. P. (2015). PORTAAL: A Classroom Observation Tool Assessing Evidence-Based Teaching Practices for Active Learning in Large Science, Technology, Engineering, and Mathematics Classes. CBE Life Sciences Education, 14(2), 14-23. Friend, M., & Cook, L. (1992). Interactions: Collaboration Skills for School Professionals. Longman Publishing Group, 95 Church Street, White Plains, NY 10601. Ganser, T. (2000). An Ambitious Vision of Professional Development for Teachers. NASSP Bulletin, 84(618), 6-12. Garet, M. S., Porter, A. C., Desimone, L., Birman, B. F., & Yoon, K. S. (2001). What Makes Professional Development Effective? Results from a National Sample of Teachers. American Educational Research Journal, 38(4), 915-945. Guskey, T. R. (2000). Evaluating Professional Development. Corwin press. Guskey, T. R. (2002). Professional Development and Teacher Change. Teachers and Teaching, 8(3), 381-391. Hargreaves, A., & Fullan, M. G. (1992). Understanding Teacher Development. Teachers College Press, 1234 Amsterdam Avenue, New York, NY 10027. Helterbran, V. R., & Fennimore, B. S. (2003). Collaborative Early Childhood Professional Development: Building from a Base of Teacher Investigation. Early Childhood Education Journal, 4(31), 267-271. Le, V. C., Nguyen, H.T.M., Minh, N.T.T., & Barnard, R. (Eds.). (2019). Building Teacher Capacity in English Language Teaching in Vietnam: Research, Policy and Practice (1st ed.). Routledge. https://doi.org/10.4324/9780429457371 Leisyte, L., & Westerheijden, D. F. (2014). Stakeholders and Quality Assurance in Higher Education. In Drivers and Barriers to Achieving Quality in Higher Education (pp. 83- 97). Brill Sense. Murray, A. (2010). Empowering Teachers Through Professional Development. In English Teaching Forum (Vol. 48, No. 1, pp. 2-11). US Department of State. Bureau of Educational and Cultural Affairs, Office of English Language Programs, SA-5, 2200 C Street NW 4th Floor, Washington, DC 20037. O’Dwyer, J. B., & Atlı, H. H. (2015). A Study of In-Service Teacher Educator Roles, With Implications for a Curriculum for Their Professional Development. European Journal of Teacher Education, 38(1), 4-20. Opfer, V. D., & Pedder, D. (2011). The Lost Promise of Teacher Professional Development in England. European Journal of Teacher Education, 34(1), 3-24. http://u.lipi.go.id/1593190689 http://u.lipi.go.id/1593190689 https://doi.org/10.4324/9780429457371 Copyright © The Author(s) Vol. 3, No. 1, January 2022 e-ISSN: 2723-4126 p-ISSN: 2776-8880 68 Parel, C. P., Caldito, G. C., & Ferrer, P. L. (1973). Sampling Design and Procedures. New York, Singapore: The Agricultural Development Council Inc. Piasta, S. B., Justice, L. M., Cabell, S. Q., Wiggins, A. K., Turnbull, K. P., & Curenton, S. M. (2012). Impact of Professional Development on Preschool Teachers’ Conversational Responsivity and Children's Linguistic Productivity and Complexity. Early Childhood Research Quarterly, 27(3), 387-400. Prediger, S., Roesken-Winter, B., & Leuders, T. (2019). Which Research Can Support PD Facilitators? Strategies for Content-Related PD Research in the Three-Tetrahedron Model. Journal of Mathematics Teacher Education, 22(4), 407-425. Richards, J. C., & Farrell, T. S. C. (2005). Professional Development for Language Teachers: Strategies for Teacher Learning. Ernst Klett Sprachen. Smith, C., & Gillespie, M. (2007). Research on Professional Development and Teacher Change: Implications for Adult Basic Education. Review of Adult Learning and Literacy, 7(7), 205-244. Teig, N., Scherer, R., & Nilsen, T. (2019). I Know I Can, but Do I Have the Time? The Role of Teachers' Self-Efficacy and Perceived Time Constraints in Implementing Cognitive- Activation Strategies in Science. Frontiers in Psychology, 10, 1697-1697. Timmermans, A. C., de Boer, H., & van der Werf, M. P. (2016). An Investigation of the Relationship Between Teachers’ Expectations and Teachers’ Perceptions of Student Attributes. Social Psychology of Education, 19(2), 217-240. Villegas-Reimers, E. (2003). Teacher Professional Development: An International Review of the Literature. Paris: International Institute for Educational Planning. Zohrabi, M. (2013). Mixed Method Research: Instruments, Validity, Reliability and Reporting Findings. Theory and Practice in Language Studies, 3(2), 254-262. http://u.lipi.go.id/1593190689 http://u.lipi.go.id/1593190689