This special issue will focus on advanced and emerging tools and methods for computational support of conceptual design. It is well recognized that conceptual design is the most critical stage in the product lifecycle and that decisions at this stage commit significant future costs. At the same time, computer support of conceptual design is lagging behind, though it has significant scope for development. In conceptual design the activities have a dynamically changing character with the goal to gather, generate, represent, transform, manipulate, and communicate information and knowledge related to various design concepts. This implies a need for increased computational capabilities, and calls for novel methods and techniques, new paradigms and models for conceptual design. Also important is to extend the creative ability of designers and to allow focusing on design innovation rather than on how to use the tools. The new methods include sketch processing, pen computing, spatial modeling; design synthesis, constraint satisfaction and configuration support, but they also address product lifecycle issues such as manufacturability, packaging and recycleability. We are soliciting original manuscripts that highlight recent successes and define major research challenges. Topics include but are not limited to: β Cognitive issues, creativity and design exploration β Information aggregation, representation, and their use for conceptual design β Computer modeling and reasoning for shape, structure, configuration, layout, function, behavior, and lifecycle in concept design β Sketch, hand motion, gesture, and verbal interfaces β Re-design and re-engineering methods