Most of the time, digital tools at school are not exploited to their full potential. The desire to use these tools (laptops, computers, tablets) to improve student autonomy, one of the school aims, questions the teacher training. The original research question is: under what conditions can teacher training contribute to the use of digital tools that promote student autonomy?

We design teacher training in a research collective following an iterative process. The goal of this training is to give to the teachers the keys to develop student autonomy using digital tools. To support this process, several collaborations between researchers and teachers were implemented in several fields (mathematics, English, physics and chemistry).

In this paper we present the Design-Based Research implemented in physics and chemistry. Three physics and chemistry teachers at middle school (pupils from 11 to 15 years old) and one researcher work together to design a classroom scenario in which digital tools are used to support student autonomy.

As defined by Amiel & Reeves (2008), the DBR is built from four steps in a constant refinement of problems, solutions, methods, and design principles:

• Analysis of practical problems by researchers and practitioners in collaboration,
• development of solutions informed by existing design principles and technological innovations,
• iterative cycles of testing and refinement of solutions in practice,
• reflection to produce “design principles” and enhance solution implementation.

Attempting to follow these principles the DBR group designed a first iteration of a physics classroom scenario about the characteristics of the sound (8^th grade, 13-14 years old student). This scenario was designed on the concept “let learn” (Coughlin, 2015) and allowed the autonomy throughout 3 or 4 courses depending of the teachers, for a total of 6 hours.

To analyse this DBR, we chose a collaborative model built on the meta-didactical transposition (MDT) framework (Aldon et al., 2013) by Sanchez & Monod-Ansaldi (2015).

As a significant concept of this model, the praxeology was defined by Chevallard (1999) as organized in two levels: the know-how (praxis) and the know-why (logos). The first one explains the tasks performed and the technique employed; the second one justifies practices from a technological and theoretical point of view.

The MDT analytical framework, including praxeology, allows us to ask our research question as follows:

To what extent does collaborative research (between teachers and researchers) allow for the sharing of praxeologies at the meta-didactic level, thus contributing to the development of digital uses that promote student autonomy?

To develop and analyse our collaborative research, we first held a collective meeting (presentation of the project, choice of sound theme, choice of 8th grade), then individual interviews (on the path, training and use of digital technology, conception of autonomy), then a second collective meeting allowed us to collectively design the sequence and activities concerning sound (practical, digital and paper). The sequence was implemented by the three teachers in 5 classes. Finally, we held a third group meeting to debrief the implementation in the classroom and discuss the limitations and opportunities to improve the sequence. Data collection The three individual interviews with teachers and the three group meetings were recorded using a voice recorder. Video recordings were made during the sessions implemented in class. Email exchanges and an online shared document were saved. Analysis We try to characterise teachers’ praxeologies in the same way as Sanchez et al. (2017) where the tagging of the data is driven by these questions: - The task (what?): What should have been done in the classroom? What do we want to do? What will the students do? - The technique used to perform the task (how?): How did the students and teachers performed the task? How did they want to perform the task? How did we want the students or the teachers to perform the task? - The technology (i.e. the justification of the technique) (why?): why did they choose this technique to perform the task? Why should this task be performed in this way? - The underlying theoretical assumptions (why do we think that?): Why do we think that this task had to be performed this way? Why do we think that they should use this way to perform the task? We use the data collected by interview and collective meeting to describe the logos while the data collected by video of the courses and also collective meeting is used to describe the praxis.

At this time, we are between the first and the second step of an iterative process. The analysis and the articulation of this data are still ongoing to characterise the praxeologies of the teachers. We aim to link this ongoing analysis to the second step of iterative process on the one hand in a dynamic point of view; then on the other hand to the teacher training designed by a collective research. We expect these results will point some key barriers allowing to improve the teacher training. This research program is supported by the French government as part of the e-FRAN component of the Future Investment Program, operated by Caisse des Dépôts

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