The application of basic science to clinical medicine has accelerated to such a degree as to require novel methods for communication of advanced information to physicians. One such device has been the popularization of conferences in specific, rapidly advancing areas of medicine with subsequent publication of the proceedings. The participants in this particular "Third Applied Seminar of the Association of Clinical Scientists" have attempted briefly to summarize certain specific and limited areas of thyroid and parathyroid function in an effort to present some basic concepts and their clinical applicability. Unfortunately, oversimplification and brevity have resulted in most of the presentations' lacking sufficient breadth and depth of content to succeed in their intended purpose. This is particularly true of the essays on methodology which barely touch critical aspects of concept or technique and serve merely to call attention to the fact that such techniques and diagnostic aids are currently available.