This article, based upon the field of comparative didactics, seeks to contribute to the
identification of generic and specific features in the teaching and learning process.
More particularly, its aim is to examine, through the study of two different school
subjects: biology and English as a second language, how passive didactic
differentiation (Sensevy et al. 2008) can develop and account for the gap in progress
growing between more able and less-able students. For our analysis, we adopt a
didactic viewpoint basing our study on what is going on in the class when the teacher
and her students interact and use notions borrowed from the Joint Action Theory in
Didactics (Sensevy and Mercier 2007; Sensevy 2011). At the end of the article, we
mainly argue that more teacher training focused on 'objects of learning' and
'knowledge-in-use' is necessary if we want teachers to be able to produce didactic
milieus adapted to students with mixed abilities and, more generally, if we want to
increase epistemic access (Morrow 2007).