ERIES Journal volume 16 issue 1 Printed ISSN 2336-2375 65 Electronic ISSN 1803-1617 TEACHER-PRACTITIONER INQUIRY IN PROFESSIONAL DEVELOPMENT: A CASE OF ADAPTATION AND RESISTANCE TO GENRE-BASED SYSTEMIC FUNCTIONAL LINGUISTIC AS A NEW WRITING INSTRUCTION ABSTRACT This qualitatve study reports the results of sensemaking when teacher-practtoner inquiry in professional development (PD) is carried out for 120 Vietnamese K-12 and college teachers. The PD was designed to prepare teachers to teach with diferent newly-approved English language coursebooks using a genre-based systemic functonal linguistc approach (SFL). During scafolds in workshops, teaching staf guided teachers in cooperatng and drafing lessons using genre-based SFL, examining the lessons’ impacts on students’ responses. Teachers also journaled to unravel the knited instructonal complexites and express their willingness to adapt to emerging teaching practces. Data were collected via the video recordings, teachers’ interviews, and content analysis of their inquiry products. Four themes representng the complexites in teachers’ sensemaking of scafolded collaboratve PD were: 1. Improved teacher agency in terms of planning and instructon; 2. Research-based experiental learning creatng a venue for intrinsic motvaton to innovate in instructon; 3. An overwhelming feeling of inequity between high and low-resourced instructonal situatons; 4. The mismatch between teachers’ advocacy for desired deep-learning approach and the traditonal ideology of rote learning for exams. KEYWORDS In-service teacher educaton, practtoner inquiry, professional development, teaching reforms HOW TO CITE Dinh H., Nguyen L. T. H. (2023) ‘Teacher-practtoner Inquiry in Professional Development: A Case of Adaptaton and Resistance to Genre-based Systemic Functonal Linguistc as a New Writng Instructon’, Journal on Efciency and Responsibility in Educaton and Science, vol. 16, no. 1, pp. 65-80. htp://dx.doi.org/10.7160/eriesj.2023.160107 Hanh Dinh 1* Lan Nguyen Thi Huong 2 1 University at Albany, United States of America 2 Hanoi Natonal University of Educaton, Vietnam * mdinh@albany.edu Artcle history Received August 31, 2022 Received in revised form December 8, 2022 Accepted February 24, 2023 Available on-line March 31, 2023 Highlights • Teacher-practtoner inquiry in professional development helps students’ sensemaking process to adapt to new pedagogical standards and motvate their commitment to change. • The values and positve outcomes of teacher-practtoner inquiry may fade out if it is not maintained in daily practces. • Challenges in maintaining the impact of teacher-practtoner inquiry could come from several internal and external factors. INTRODUCTION Enhancing the quality of Vietnamese foreign language instruction is one of the fundamental missions in the process of creating a globally competitive and innovative national educational system in the 21 st century (Hoang, 2016; Nguyen, 2017; Tran, 2014; Tran et al., 2021). Language policy about reforms in English language instruction emphasizes the essence of investing in improving the teaching capacity of in- service teachers through a sustainable and consistent teachers’ professional development (PD) plan (Canh, 2002; Le et al., 2022; Nguyen and Burns, 2017; Nguyen and Newton, 2021; Thao and Mai, 2022). Nevertheless, the extent to which the PD accomplished its objectives and succeeded in improving English profciency and pedagogical capacities of teachers at all educational levels is still a matter of debate, with academic and public discussions on the gaps between expectations and reality in planning, managing, and implementing the PD. For example, when the Ministry of Education (MOE) in Vietnam launched an efort in decentralizing the English language textbook last year so that schools can choose the Full research paper