This paper aims to figure out in what extent teachers' approaches and practices with respect of IBST could be altered by teacher education and training programmes vs teachers' experience. A 6 dimensions model results from the state of the art about IBST (Grangeat, 2010). Three groups of 6 teachers each are compared. 1/ Committed science teachers are involved within CPD programmes based on teacher collaboration. 2/ New science teachers intended, during their first year as teacher, to a specific training programme based on controversy. The third group gathers 6 ordinary science teachers who could only apply on their own experience. Data are collected through videotaped IBST sessions and interviews about the video. All lessons and interviews are transcribed. On each of the 6 dimensions, each ST is given a score. The median of the three groups could be compared. The results show that learners-centred teaching approaches and practices are foster by CPD programmes which involve teachers in a collective work in order to design resources for other teachers or common position with respect of professional points. Nevertheless, through the 3 groups, 'questioning' and 'explanation' are the dimensions which seem the most teacher-centred.