In recent years microstructural analysis has been a rapidly changing field of scien­ tific endeavor. No longer are the efforts of the microstructural analysts (sometimes referred to as metallographers, materialographers, ceramographers, and similar desig­ nations) limited to the tasks of polishing, etching, and photographing specimens of materials. The performance demanded of materials used for many current applica­ tions requires much more complete characterizations than were possible only a scant few years ago. Although the individuals who have been expected to develop new and improved techniques to permit these required characterizations have been severely challenged, in large part they have met the challenge. In view of the many new developments in the field of microstructural analysis and recognizing the requirements to communicate these developments to the wide audience that might make use of them, the American Society for Metals and the In­ ternational Metallographic Society joined forces to co-sponsor a symposium that was intended to bring participants and attendees up to date on the subject "Inter­ pretive Techniques for Microstructural Analysis". This symposium was held in Min­ neapolis, Minnesota, USA, June 29 and 30, 1975. It followed two earlier symposia co-sponsored by the same two societies on other subjects of current interest to the metallographic community, Microstructural Analysis - Tools and Techniques, 1972, and Metallographic Specimen Preparation - Optical and Electron Micros­ copy, 1973.