This article proposes a state of the art of the paradigms and methodologies that have been used to study surfing on the Web and uses of computer technology over the past ten years. In a critical overview, the author shows how different disciplines have approached trajectories on the Web from different angles and by means of diverse methodologies, ranging from the analysis of traces on servers to the observation of users in real-life situations. The methodological approach followed in the Entrelacs panel is based on an individual probe to observe the uses of a qualified and representative cohort of users. The author shows the advantages and difficulties of this type of approach aimed at combining a global view with local contextualization.