This volume represents a rst attempt to bring together ideas from two pre- ously unrelated research areas, namely Software Engineering and Computational Re'ection, and to evaluate the bene ts that each can bring to the other. Computational re'ection, or for short re'ection, is quite a young discipline that is steadily attracting attention within the community of object-oriented researchers and practitioners. The properties of transparency, separation of c- cerns, and extensibility supported by re'ection have largely been accepted as useful for software development and design. Re'ective features have been in- TM cluded in successful software development technologies such as the Java l- guage. Re'ection has proved to be useful in some of the most challenging areas of software engineering, including component-based software development, as demonstrated by extensive use of the re'ective concept of introspection in the TM Enterprise JavaBeans component technology. Nevertheless, there are still c- nitive barriers separating re'ection from the discipline of software engineering, and, more speci cally, object-oriented re'ection from object-oriented software engineering. Only a few authors have begun to explore the opportunities o ered by the inter-disciplinary application of concepts from re'ection and software - gineering, that is, from the novel research area of re'ective software engineering. It is our belief that current trends in ongoing research in object-oriented re'ection and software engineering clearly indicate that an inter-disciplinary - proach would be of utmost relevance for both. The overall goal of this volume is to support the circulation of ideas between these disciplines.