Interaction (i.e., talking and collaborating) between leaders and teacher leaders functions as a source to build expertise in inquiry-based working (Daly & Finnigan, 2010). Such interaction supports the dissemination of beliefs and knowledge; prerequisites for working inquiry-based on educational improvement (Spillane et al., 2012). Inquiry-based working refers to combining practical experiences with knowledge from existing research (Baan, 2020). However, this interaction about inquiry-based working is not a given (Geijsel et al., 2020). This study focuses on the research question “How does the interaction between leaders and teacher leaders manifests regarding inquiry-based working on educational improvement?". Leaders and teacher leaders (N= 205, response rate 68%) from eight Dutch secondary schools completed a questionnaire with two items: "With which colleagues did you talk about inquiry-based working to improve education?" and "With which colleagues did you collaborate inquiry-based to improve education?" We analyzed and visualized these social network data using Gephi. Over all the schools, leaders and teacher leaders talk more about, than collaborate on inquiry-based working. Regarding talking, small groups (islands) of leaders and teacher leaders, as well as teacher leaders who talk with just one colleague, are visible. Leaders generally talk more about inquiry-based working with colleagues than teacher leaders do. Regarding collaboration, larger schools have more collaborating small groups. At each school, research leaders work together with other leaders and teacher leaders in varying combinations. Interactions mainly takes place between a few leaders and teacher leaders. Sometimes these interactions occur in small groups and sometimes between individuals. This can be explained by organizational structures and routines (Spillane et al., 2012). Findings imply that school leaders have an important role in changing routines by focussing on aspects: (1) school leaders connect school improvement goals with inquiry-based working to improve education in teams and classrooms; (2) school leaders formulate clear expectations about inquiry-based working and monitor related practices within their school teams.

Baan. J. (2020). The contribution of academic teachers to inquiry-based working in primary schools [Doctoral dissertation, University of Amsterdam]. Amsterdam. https://dare.uva.nl/search?identifier=ac074b63-4c34-433d-ac5b-883247f1b39d Daly, A., & Finnigan, K. (2010). A Bridge between Worlds: Understanding Network Structure to Understand Change Strategy. Journal of Educational Change, 11(2), 111-138. http://dx.doi.org/10.1007/s10833-009-9102-5 Geijsel, F., Schenke, W., van Driel, J., & Volman, M. (2020). Embedding inquiry‐based practices in schools: The strategic role of school leaders. European Journal of Education, 55(2), 233-247. https://doi.org/10.1111/ejed.12395 Spillane, J., Kim, C., & Frank, K. (2012). Instructional advice and information providing and receiving behavior in elementary schools. American Educational Research Journal, 49(6), 1112-1145. https://doi.org/10.3102/0002831212459339