Professional vision in action: an exploratory study.

For the past two decades, much of mathematics teacher education and professional development has focused on helping teachers develop their subject matter knowledge and pedagogical content knowledge (Shulman, 1987). The idea has been that teachers need a deep understanding of mathematics, and one that is pedagogical in nature. More recently, researchers and teacher educators have begun to consider how teachers apply this knowledge in planning for and carrying out instruction (Franke, Carpenter, Levi, & Fennema, 2001; Lampert, 2001). Of particular concern are the ways in which teachers employ knowledge in the very moments of instruction, when they are leading discussions or interacting one-on-one with students.

Given the current context of reform in the U.S, the in-the-moment demands that mathematics teachers encounter have become increasingly great. Rather than carefully follow a pre-planned lesson, mathematics teaching today calls for a great deal of on-the-fly decision making (Smith, 1996; Wallach & Even; 2005). Teachers must be able to quickly diagnose students' thinking, decide whether or not to pursue an unexpected tangent, and continually assess the progress of an on-going lesson. Other researchers have also noted the importance of this kind of expertise both for teaching in general (e.g. Berliner, 1994; Rodgers, 2002), and more specifically for the teaching of mathematics today (Ball, & Cohen, 1999; Chamberlin, 2005).

Many kinds of knowledge must be brought to bear by teachers during the moments of instruction. In prior work we have focused on one aspect of this knowledge that we call professional vision. Goodwin (1994) coined the term professional vision to characterize the specialized way that members of a professional group look at the phenomena of interest of them. Thus, a detective's professional vision allows him to make sense of a crime scene, and an architect's professional vision allows the architect to recognize key features in the design of buildings. A teacher's professional vision, on the other hand, is concerned with the phenomena of classroom interactions. More specifically, teachers' professional vision involves the ability to notice and interpret significant interactions in a classroom (Sherin, 2001, 2007).

The study of teachers' professional vision poses some unique challenges. The application of professional vision happens in a manner that is fleeting, and that is distributed through the moments of instruction. Because of the ongoing nature of instruction, it is not realistic to expect that one could "pause" instruction momentarily, ask a teacher what he or she is attending to at that moment, and then continue uninterrupted. To address this problem, we have relied extensively on video as a tool for studying professional vision. We asked teachers to look, retrospectively, at short excerpts of video that we had collected of their own teaching, or the teaching of others.

In this article, we report on our attempts to employ a new technological solution to study professional vision in action. We have recently begun to explore the use of a new kind of tiny wearable video camera that can be worn by teachers in order to capture classroom events from their own perspective. Our purpose here is to, first, draw some initial conclusions about the viability of this new technological solution as a means through which to study professional vision, and to perhaps enhance it. Second, we will report on some of our first attempts to use the camera to answer basic questions about the nature of teachers' professional vision as it is applied in action. Working with one high school mathematics teacher we ask: (a) What kinds of events stand out to the teacher during instruction? and (b) To what extent can the teacher articulate why those events are significant?

Using Video To Study and Enhance Professional Vision

Several attributes of video indicate that it might be a valuable media for exploring teachers' professional vision. First, video appears to capture much of the complexity of classroom interactions. While the perspective of the videographer certainly influences what aspects of classroom interactions are portrayed (Goldman-Segall, 1998), video has the potential to richly represent classroom environments and the multiple actions that take place simultaneously. Second, video provides a permanent record that can be viewed repeatedly. Thus unlike a live moment of teaching that is over in an instant, video allows one to preserve an interaction for later consideration. And rather than having one's memory--which can vary--serve as the record, video documents what took place in an unwavering format (McAdams, 1993). Third, when viewing video, teachers do not need to respond with the immediacy that is typically required during instruction. Instead watching video can be a time for teachers to engage in extended reflection on what is taking place in a lesson and why.