Introduction to the special issue: Renewal and reconceptualization of supervision in TESOLJointly, we, the guest editors of this special issue, have spent over 100 years in the field of TESOL experiencing various aspects of supervision of instruction-from being ESL/EFL teachers ourselves, to receiving feedback, mentoring colleagues informally, and formally observing scores of in-service and preservice teachers in our respective Master of Arts (MA) in TESOL programs. We have led the training process for others as they carry out classroom observations, and we have researched effective supervision and observation practices in our own research, including collaboratively with our PhD students. Over the years, we have carried out more classroom observation and feedback episodes (which we refer to as supervision in this special issue) than we can recall-yet this work, so vital in developing teachers' skills and impacting student learning, is one of the aspects of TESOL least explored in the scholarship. For this reason, we are exceptionally grateful to Kristen Lindahl and Bedrettin Yazan, the lead editors, for their vision in allowing us to bring this collection to the TJ audience.Broadly speaking, supervision is enacted in a remarkably consistent manner throughout the world's ELT classrooms: a supervisor observes a classroom lesson, then discusses this lesson with the teacher at some point afterwards (Cirocki et al., 2020). In addition, the supervisor may document and/or reflect on the feedback and complete a checklist, rubric, or evaluative form that rates the lesson. Yet little is known about the mindset, knowledge base, or training of the supervisor; what actually occurs at the cognitive or affective level for the teacher, student, or supervisor during the observation; or how the subsequent feedback actually changes teachers' behaviors or leads to improved student learning.While there have been seminal publications (e.g., Bailey, 2006;Fanselow, 1988;Gebhard, 1991) that consider supervision in TESOL through a practical or theoretical perspective, most of the empirical research on supervision in our field is situated in examinations of the post-observation feedback conversation. This research has clearly indicated that supervisors, despite best intentions, tend to dominate the talk, tell rather than ask, and do the work of noticing, unpacking, and processing for the teacher (Copland et al., 2009;Farr, 2010;Orland-Barak & Klein, 2005). These studies have contributed vastly to our understanding of the nature of this talk and provided insights that have helped supervisors (and us personally) be more reflective, strategic, and alert when carrying out these complex interactions (Farrell, 2017). Research on these conversations has led us to adopt new methods within the supervision cycle, such as the use of video, to foster more impactful and empowering experiences for teachers learning post-observation.The world of teaching has rapidly evolved, and supervisory practices that were common in the past have been advanced throug...