Situated learning plays a key role in internships and other practice-based learning settings in teacher education. The dominant assumption for a long time has been that the development of teaching competency is advanced most through practical teaching experience and post-lesson conferences between mentor and student teachers. It is through the reflection of teaching and classroom processes that student teachers are believed to develop their professional knowledge. The assistance of such reflection draws on mentor teachers’ teaching expertise. Mentor teachers, however, rarely explicate practical and theory-based knowledge underlying their practice and student teachers are not inclined to search for their mentor teacher’s underlying knowledge. As a consequence, the knowledge underlying effective teaching often remains implicit.
The symposium brings together three novel approaches to assist teacher learning, which aim to make knowledge of teaching explicit. To bridge the gap between mentor and student teachers’ instructional concepts, the method of videobased tagging as a pre-requisite to initiate and structure professional dialogue is suggested and researched by van den Bogert, Crasborn, Bruggen and Eindhoven in The Netherlands. The second study by Staub, Waldis, Schatzmann and Futter investigates effects of an intervention with mentor teachers in Switzerland, suggesting the enactment of pre-lesson conferences and/or the use of a core concepts for lesson planning and reflection. A third study involving Germany and Switzerland by Kreis, Schnebel, Wyss, Wagner and Deiringer researches student teachers’ knowledge, beliefs and experiences related to collaborative lesson planning with peers. The shared assumption is that all three approaches enhance explicit communication on teaching and encourage professional dialogues that contribute to teacher learning in significant ways.

Eliciting mentor and pre-service teachers’ practical knowledge using teacher-tagged classroom situations
Bogert van den, Crasborn, Bruggen van & Jochems)

Objectives
The present study has a twofold objective. First, elicitation of mentor and pre-service teachers’ conceptualizations of videotaped classroom situations to clarify similarities and differences between practical knowledge of experienced and novice teachers. Second, exploration of ‘collaborative tagging’ as a new method to access mentors and pre-service teachers’ practical knowledge.

Theoretical framework
Teachers’ practical knowledge underlies overt teaching behavior, and is personal, unique, often tacit, and intertwined with teaching actions (Meijer, Verloop, & Beijaard, 2002). The ability to notice and interpret what is happening in a classroom is a basic aspect of teachers’ practical knowledge (Goodwin, 1994). Experienced teachers are more proficient in this essential perceptional process than novice teachers (Berliner, 2001; Sabers, Cushing, & Berliner, 1991). Consequently, proficient teachers may facilitate the professional development of novices. However, mentor teachers rarely explicate practical knowledge underlying their teaching practice (Edwards & Protheroe, 2004), and most pre-service teachers are not inclined to search for their mentor teacher’s practical knowledge (Penny, Harley, & Jessop, 1996).
Hence, in this study we explored ‘collaborative tagging’ (Mika, 2005): a method where many people independently attach keywords called tags to e.g. videos, for categorization and fast future retrieval. Collaborative tagging has gained popularity since 2004 (Hammond, Hannay, Lund, & Scott, 2005), indicating the willingness and ease with which this activity is undertaken. In other studies (Cattuto, Benz, Hotho, & Stumme, 2008; Mika, 2005) network analysis of the co-occurrence of tags revealed the semantic relationships between the tags; a bottom-up taxonomy, or a so called folksonomy (Vander Wal, 2004). In this study, collaborative tagging was applied to explore the structure of teachers’ knowledge and compare conscious aspects of mentor and pre-service teachers’ practical knowledge. The main research questions were:
• Which concepts do mentor- and pre-service teachers use to tag videotaped classroom situations?
• To what extent do the generated tags and the relations between them differ between mentor- and pre-service teachers?
• To what extent is collaborative tagging is helpful in gaining access to conscious aspects of mentors and pre-service teachers’ practical knowledge?
Method
Participants were 100 mentor-teachers and 100 pre-service teachers. The participants each ‘tagged” five video-fragments of different classroom situations. Data were analyzed with UCINET software as proposed by Mika (2005). Co-occurrences of tags were computed. Familiar measures of social network analysis (e.g. clustering coefficients, and (local) betweenness centrality) were used to describe each folksonomy, and to compare pre-service and mentor teachers’ networks of tags.
Results and significance
The study established that tagging is a promising new method to elicit teachers’ practical knowledge. The resulting folksonomies clarified similarities and differences between mentors’ and pre-service teachers’ practical knowledge. Results indicate that experienced teachers use more detailed and specific tags than pre-service teachers. This method makes a significant contribution to the methodology of the study of teachers’ practical knowledge. Folksonomies not only elicit individual teachers’ practical knowledge but enable researchers to discern common element’s in teachers’ practical knowledge. Moreover, in teacher education, folksonomies are helpful to initiate and structure professional dialogue between pre-service and mentor teachers.