WP4d: Report on IBST and the Pairform@nce project: creating training paths Pairform@nce is a national teacher training project in France. It proposes training packages (called training paths), providing resources for the organization of blended teachers training sessions, using a distant platform. The training follows a principle of collective elaboration of lessons, which permits the emergence of teachers' communities, sharing a repertoire of resources (Gueudet & Trouche 2008, Gueudet 2008). The implementation by the teachers of collectively designed lessons permits the development of innovative teaching practices. In this report we present the Pairform@nce project through an analysis of two IBST-oriented training paths. The first one, called "Inquiry in mathematics with dynamic