REPRESENTATION is a wide umbrella that covers different disciplines such as design, arts, architecture, cinema, literature, politics, economics, semiotics, etc… We may even say that representation is in every act of human beings whenever they think about something. This fundamental role of representation makes it very critical in the design process, thus the whole design process is based on the dialogue between the inner and outer representations. In this third issue of UOU Scientific Journal we would like to focus on the nature of representation, its own ontological aspects, materiality, immateriality and its crucial role in the design process rather than its metaphorical side related with politics and semiotics.