Why introduce ICT in schools? If we challenge educational reformers and practitioners with such a question, we find a lot of ambiguous answers, depending mainly on the kind of different expectations that ICT raise. To better understand the educational role of ICT, it is important to reveal the underlying assumptions one expects when proposing their introduction in schools. In order to establish a conceptual frame for a technological policy, the author distinguishes three levels of justifications: macroecological (or ethical), strategic (or innovative), and microecological (or ergonomic-didactic). Some critical points have to be considered at each level. The problem of ICT effectiveness concerns only the latter level, where the so-called "cognitive technologies" and the possible integrations between ICT, mind, and educational strategies, deserve special attention. (Contains 1 figure.)