Abstract : The many surveys about information usages in academic environment tend to rest on the model of the generational digital divide, according to which the academic world is impacted from outside by the "digital natives" usages. As a consequence, they tend to evaluate students information practices according to the distance from the "good practices" as conceived by the mediators. A non-normative evaluation mode, based on efficiency, could give a better view on the diversity and inventivity of the strategies. Such an evaluation implies a new understanding of those information retrieval. Through three lines of questioning (knowledge of ressources, critical appropriation of interfaces, reassumption of subjectivity) we give a sketch for a new paradigm, that of a "fuzzy search" wich associates mastering the tools according to the relevance criteria with serendipity as implying the trained aptitude to greet the unexpected.