Digital natives are the potential users of many applications designed and built today. For this generation most of state of the art features related to social interactions and ubiquitous computing will be taken as granted. For this reason, we have to provide design frameworks and methodologies that integrate these features at early design stages. In this paper we propose a framework for designing Social Interactive Systems (SIS) based on four criteria: identity, space, persistence and action. In order to demonstrate the usefulness of the framework the paper will describe an experiment we held with a Social Virtual World developed using the above-mentioned framework.