The work in the first chapter investigates whether and how to design for perceptive qualities in artefacts. By designing perceptive qualities in the artefact, person and artefact hypothetically are able to engage in a rich reciprocal interplay of perceiving and being perceived. Perceptual crossing happens between them, and they share their perception of their common space. They can build a common history, which positively influences the person's feeling of involvement. In the course of their interaction, both person and artefact come to appreciate each other's viewpoint; they appreciate that they affect each other. The intelligence of the artefact is built in the course of this interaction.
Through several iterations of designing, building and evaluating PeP and PeP+ (perception Pillar), it is shown that person and artefact can engage in this reciprocal interplay of perceiving and being perceived. The research artefacts function has physical hypotheses. Different behaviours of PeP and PeP+ are compared and evaluated in three experiments. Throughout this process a set of design notions developed that inform design-researchers and design-practitioners on designing for perceptive qualities. The different iterations showed the state of the art of the development of the design notions at that moment of the process. The phenomenon of perceptual crossing between person and artefact, and whether or to what extent the rich reciprocal interplay happens is shown and closely investigated.