Author's note:  People too numerous to mention, from several organizations, have supplied many of the ideas that are presented in this document, in the course of discussions of these issues at meetings and in private conversations.  My thanks to all. 

I want to mention two people in particular, Walter Schneider and David Osterman, for their help in tracking down cite-able evidence for some of the points, at a time when I was desperately scrambling to meet a deadline. 

-E. Tarkington, 04Mar98 

(This note does not appear in the version submitted to the committee.)