Search queries on biomedical databases, such as PubMed, often return a large number of results, only a small subset of which is relevant to the user. Ranking and categorization, which can also be combined, have been proposed to alleviate this information overload problem. Results categorization for biomedical databases is the focus of this work. A natural way to organize biomedical citations is according to their MeSH annotations. MeSH is a comprehensive concept hierarchy used by PubMed. In this paper, we present the BioNav system, a novel search interface that enables the user to navigate large number of query results by organizing them using the MeSH concept hierarchy. First, the query results are organized into a navigation tree. At each node expansion step, BioNav reveals only a small subset of the concept nodes, selected such that the expected user navigation cost is minimized. In contrast, previous works expand the hierarchy in a predefined static manner, without navigation cost modeling. We show that the problem of selecting the best concepts to reveal at each node expansion is NP-complete and propose an efficient heuristic as well as a feasible optimal algorithm for relatively small trees. We show experimentally that BioNav outperforms state-of-the-art categorization systems by up to an order of magnitude, with respect to the user navigation cost. BioNav for the MEDLINE database is available at http://db.cse.buffalo.edu/bionav.

Search queries on biomedical databases like PubMed often return a large number of results, only a small subset of which is relevant to the user. Ranking and categorization, which can also be combined, have been proposed to alleviate this information overload problem. Results categorization for biomedical databases is the focus of this work. A natural way to organize biomedical citations is according to their MeSH annotations, a comprehensive concept hierarchy used by PubMed. In this paper, we present the BioNav system, a novel search interface that enables the user to navigate large number of query results by organizing them using the MeSH concept hierarchy. First, the query results are organized into a navigation tree. Previous works expand the hierarchy in a predefined static manner. In contrast, BioNav uses an intuitive navigation cost model to decide what concepts to display at each step. Another difference from previous works is that the hierarchy is not strictly displayed level-by-level.

We demonstrate the BioNav system, a novel search interface for biomedical databases, such as PubMed. BioNav enables users to navigate large number of query results by categorizing them using MeSH; a comprehensive concept hierarchy used by PubMed. Once the query results are organized into a navigation tree, BioNav reveals only a small subset of the concept nodes at each step, selected such that the expected user navigation cost is minimized. In contrast, previous works expand the hierarchy in a predefined static manner, without navigation cost modeling. BioNav is available at http://db.cse.buffalo.edu/bionav.