This summary article resulted from an informal discussion period held during the International Conference on Precision Electromagnetic Measurements, August 14-17, 1962. This session was presided over by Prof. Norman Ramsey of Harvard University. The Radio Standards Laboratory of the National Bureau of Standards in Boulder, Colorado, sponsored the meeting along with the IRE Professional Group on Instrumentation and the AIEE Instrumentation Division. Partial support for the conference came from a grant from the National Science Foundation.