This book contains a selection of revised versions of papers presented at the Third Eurographics Workshop on Intelligent CAD Systems, which was held at Hotel Opduin on the island of Texel in The Netherlands, April 3-7, 1989. The workshop theme was Practical Experience and Evaluation. It included five paper presentation sessions, each followed by a discussion. The workshop closed with a general discussion. The book is therefore divided into five parts: design process, system architecture, languages, geometric reasoning, and user interface. A report on the discussion session, written by the session's moderator, concludes each part. These reports are not intended to be exact records of the discussion, but rather the moderators' summary of their contents. The aim of the workshop was to share the experience the participants gained by developing intelligent CAD (Computer Aided Design) systems, and to evaluate the developed systems to determine which features were still lacking. The workshop was organized as the last one in a series of three workshops under the same title. The first workshop focused on theoretical and methodological aspects, resulting in a sound theoretical basis for intelligent CAD systems. Implementational issues were discussed at the second workshop, paying attention to systems developed with reference to this basis. The experience and evaluation showed a dual outcome. Firstly, it resulted in the development of a new generation of intelligent CAD systems. Secondly, it led us to the development of new theories for intelligent CAD.