Evaluation culture runs the risk of over rationalisation. In order to evaluate programs, educational systems as well as the reforms themselves, experts require these to show objectives that are explicit, clear and stable and to hold fast to these objectives. On the other hand, the sociological approach favored by the organisations and the school systems suggests that the goals should remain vague enough to be acceptable in a pluralistic society, that the decisions leading to reforms should integrate the contradictions of the systems and of it's limited rational and finally that the final evaluation of reforms usually occurs when these are almost forgotten. The only avenue relative to programs, pioneered by Scriven, is to do a formative observation of these school reforms, by first focusing most of the attention to teaching practices and to learning conditions rather than to measurable contents acquired by the learners.