A review of marginality theory shows some gains on the psychological front but little advance, since Stonequist's work, in the sociological sector of the marginal situation and its effects on the structure and functioning of the group. Combining an hierarchical approach with the notion of inconsistency in rankings, a sociological definition of the marginal situation is suggested. Such a definition provides clarification of the nature of the marginal situation, a framework within which the variety of marginal situations may be located and also makes easier the hitherto neglected analysis of the effects on a group of being in such a situation.