Intractable problems in novelty and diversity

Abstract

Versión electrónica de la ponencia presentada en la XVI Jornadas de Ingeniería del Software y de Bases de Datos (JISBD 2011), celebrada en 2011 en A CoruñaInformation retrieval’s basic problem is retrieving a set of documents relevant for a given query. Here, we present three classes of methods that appeared in the liteature, as well as a new one, which is an improvement of the one the three, to retrieve result sets that, in addition to relevance, try to maximize diversity and novelty. We analyze the complexity of these problems and show that whenever relevance, diversity, and novelty are considered together, the methods are all NP-complete.This work was supported in part by the Ministerio de Educaci´on y Ciencia under the grant N. MEC TIN2008-06566-C04-02