presentations, poster sessions, and discussions. The symposium benefited from the insight of two keynote speak­ ers, Dr. Harris Burte of the Materials Laboratory, AFWAL, and Mr. Ward Rummel of the Martin Marietta Corporation, who presented complementary messages. Dr. Burte pointed out the need to identify "windows" to serve as guides for focusing NDE research. The "window" concept may be thought of as an opportunity for the application of NDE technology to an important problem and, through this application, to identify knowledge gaps which must be filled by generic research. This concept simultaneously provides a mechanism for the solution of a direct ap­ plication problem and a set of strong guidelines for generic research directions. Mr. Rummel called attention to the value of "lessons learned" from var.