Relying on the Cluster Hypothesis, which states that relevant documents tend to be more similar one to each other than to non-relevant ones, most of information retrieval systems producing search results as a set of clusters seek to gather all relevant documents in the same cluster. We propose here, by the settlement of new evaluation measures, to reconsider the benefits of the entailed concentration of the relevant information. Contrary to what is commonly admitted, we finally show that systems realizing a distribution of the relevant information may be at least as useful for the user as systems gathering all relevant documents in a single group. MOTS-CL