Introduction

Not the least of the important events in library history occuring in 1876 was the appearance of a (then) anonymous publication entitled: A Classification and Subject Index for Cataloging and Arranging the Books and Pamphlets of a Library. We now know that the author was Melvil Dewey and, through the years, the work has become known as the Dewey Decimal Classification (DDC). The twenty-first annual Allerton Park Institute of the University of Illinois Graduate School of Library Science honored this modest beginning of modern library classification on the eve of its centennial. Forest Press (Albany, N.Y.), publisher of the DDC, served as cosponsor of the conference held from Sunday, November 9, through Wednesday, November 12, 1975, at Allerton Park (the university's conference center) near Monticello, Illinois. From the first conversations concerning the conference, the intention was that the conference concentrate on classification in general and that it should be critical and objective, and not simply expository and laudatory with regard to DDC. Since Dewey's classification scheme has had a major impact on library classification and subject retrieval systems throughout the world, it was felt that the conference should include papers and discussions from leading experts in the field from the United States, Canada, and England. While the focus remained on Dewey, past, present and future, other major systems were to be noted and compared with DDC.published or submitted for publicatio