We propose a basic set of desirable properties for an abstract model of collaborative dialogue among agents. The abstraction comprehends the underlying logic of the agents, as well as the interaction protocol. The properties pursue the characterization of finite dialogues, with reasonable conclusions (based on what the participants have said), in which everything said is relevant and everything relevant is said. To this end, two levels of relevance (direct and potential ) are defined, based on the notions of inference and abduction, respectively. Illustrative examples, using mainly the DeLP formalism, are provided.Workshop de Agentes y Sistemas Inteligentes (WASI)Red de Universidades con Carreras en Informática (RedUNCI
