Defining software requirements is a complex and difficult process, which often leads to costly project failures. Requirements emerge from a collaborative and interactive negotiation process that involves heterogeneous stakeholders (people involved in an elicitation process such as users, analysts, developers, and customers). Practical experience shows that prioritizing requirements is not as straightforward task as the literature suggests. A process for prioritizing requirements must not only be simple and fast, but it must obtain trustworthy results. The objective of this paper is to provide a classification framework to characterize prioritization proposals. We highlight differences among eleven selected approaches by emphasizing their most important featuresII Workshop de Ingeniería de Software y Bases de Datos (WISBD)Red de Universidades con Carreras en Informática (RedUNCI)