Common material representations and highlighting systems
As we noted above, teachers do not engage in the sort of collaborative gazing activities that Goodwin observed among archeologists, or indeed, that linguistic ethnographers engage in. Moreover, while the archeologist can hold her object of observation steady while she examines it - for example, spraying a sample of dirt with water in order to accurately gauge its colour - the objects of teachers' gazes are dynamic, and talk back. Teachers' professional visions are formed for the most part while interacting with pupils - alone, without professional colleagues. Teachers do collaboratively look at representations of practice, but most of these are relatively indirect artefacts of teaching and learning such as lesson plans, worksheets, pupil work and examinations, or bureaucratic artefacts such as report cards and official documents in which schools provide accounts of policy compliance and/or pupil progress. We see these two phenomena - that teachers' professional visions for the most part emerge and are developed outside of collaboration and discussion with colleagues, and that when teachers do collaboratively discuss artefacts of practice, these tend to be relatively indirect representations of what actually happens in the classroom - as critical factors shaping the lack of a shared language for precise description of classroom activity.
Linguistic ethnographic analyses, in contrast, are largely based upon - and therefore better adapted to - audio- and video-recordings of classroom practice (and accompanying transcripts). Linguistic ethnographers also collect data from supplementary sources, such as fieldnotes, pupil work, lesson plans and curricular materials, but these are typically viewed as secondary, useful for contextualising the event but not worthy of the same level of attention as the core, recorded data, certainly in this context. (See Roberts  and Agar  on the distinction between core and contextual data. The status of non-recorded data is a point of contention among linguistic ethnographers; see Snell & Lefstein, 2015, for a discussion of some of the institutional pressures that privilege analysis of recorded data sets.)
Recordings are a partial representation. They capture a certain point of view - i.e. where the camera and/or microphone are positioned, and what they focus upon. They also reflect a selection: we tend to select clips that include some unusual or surprising event, that are relatively self-contained (i.e. have a beginning, middle and end) and last no longer than 5-7 minutes. Recordings are transcribed in detail, and the transcript often becomes the main object of participants' gaze. The transcript is a material representation that stabilises the ephemeral nature of interaction and affords close scrutiny of whatever the analyst has chosen to highlight. This naturally leads to greater attention to the most audible words spoken, and to the speakers, than to non-verbal communication, to intonation patterns, to quiet asides, and to non or less vocal participants. Though we often emphasise that the transcript is just a work-space, and that analysis must be performed on the recording itself, we typically return to the recording primarily when controversies arise around competing interpretations of specific sections of the transcript. (See also Lefstein & Snell  on how the transcript lends itself to event-focused micro-analysis, and tends to limit possibilities for longitudinal analysis of processes and biographies).
Recognition of the differences between the material representations that each group is accustomed to working with is useful for making sense of the researcher-teacher encounters that took place in the data analysis workshops. By basing the discussions on video-recordings and detailed transcripts we required the teachers to work with materials to which they are relatively unfamiliar, and which are less well-suited to their pedagogical perspective. This imbalance was of course compounded by the fact that one of us was also the course lecturer, tasked with assessing the course participants.