Over the past years, numerous software applications have been realized which support various aspects in architectural design. These systems help the designer in various ways: they provide drafting support, they allow a variety of photorealistic visualizations, they provide very diverse calculation and simulation aids for structural, thermal, acoustic and other aspects of the design. Yet, despite the richness of the design tools currently available, various deficiencies remain in the way in which they can be used to effectively support design activities. Several aspects of design, in particular there where the designer's knowledge, expertise and past experiences are involved, remain essentially without proper information system support. This thesis addresses the question embodied in the above statement: why is it that computer-based design aids still lack in providing full design support? It turns out that various effects are in play, all in some way related to deficiencies in the information exchange (1) among software components, as well as (2) between software components and the designer. The first deficiency relates to the issue of interoperability between information systems that has been distinguished in various domains, not only architectural design. The second deficiency relates to the mismatch that is typically encountered between functionality provided by information systems and the functionality supposedly wanted by the end user. Also this deficiency is not only encountered in architectural design. These two main lines of investigation are followed throughout this thesis. As such, it is investigated in what ways and to what extent design activity -commonly called design thinking- could be supported by information systems.