-Teacher: producer and/or translator of knowledge? Working within the social-cultural rainbow of the classroom. In this text after some epistemological and methodological comments, it is argued that, when working in a diversity of social and cultural contexts, and wanting learning processes to be meaningful to students, teachers will have to be more than knowledge translators. They also will have to be researchers. They will have to produce knowledge in order to adequately diversify the learning process through differentiation pedagogical devices. This is a text that reflects, enhance and cross contributions arising from previous works carried out mainly in collaboration with Stephen R. Stoer.