The thesis claims that an experiential approach to design really does promise the possibility of scientific design of everyday life. The purpose of this thesis is to show the promise. René Descartes conceptualized the classical formulation of a mind-body dichotomy. Various resulting and unbalanced dichotomies, such as subjective-objective, internal-external, experiential-practical and so on, raise serious concerns surrounding the concept of design. The thesis raises a crucial issue about the imbalance between technological and human concerns in the context of human-computer interaction, an imbalance that has been caused partly by the mechanistic aspect of informatics and its impact on designing human computer interaction. The thesis first explores the origin of design as a distinct activity during the industrial revolution, and reviews the tide of design history from then until today. The brief review of design history indicates that design is not merely the skill of making things or presentations. This gives direction to how design can be positioned in our modern information society. Second, the author starts a critical discussion about ordinary design approaches that, it is suggested, may have hindered true human-centred design, and then introduces an alternative approach to design and research, which the author calls Human-Experiential Design. Third, the notion of Tangible Presence in Blended Reality Space is introduced. The conceptual grounding that illustrates the experiential approach to interaction design is discussed. Fourth, the thesis presents use cases and provides examples of Human-Experiential Design in specific practical contexts. The concrete examples suggest that the emphasis on ‘balance’ or appropriate blending is very important in the development of better interactive systems for health, capitalizing on seamless combinations of the virtual and the physical in Blended Reality Space. As exemplified in the thesis, the human-experiential approach, striving for optimal combinations of tangibility and evoked presence, offers a promising tool in designing for special needs groups such as elderly people with some cognitive weaknesses, and children undertaking physical rehabilitation programmes. It is suggested that such virtual-physical blends will release human beings from the strain that existing perceived dichotomies bring. Finally, the author concludes by offering a way forward, a way that is neither subjective nor objective but rather a meaningfully integrated blend of the dichotomies, which responds to the question of what it means to be human.