This study was submitted in partial fullillment of the requirements for the degree of Doctor of Philosophy in Library Science in the Graduate College of the University of lllinois, 1954.
Though the responsibility for this work is mine alone, in many ways it has been a cooperative undertaking. I am glad to have this opportunity to record my appreciation for the advice, informa- tion, and encouragement which have done so much to enable me to carry the study to completion.
My greatest debt is to Dr. Leslie Whittaker Dunlap, who has variously acted as supervisor, class instructor, adviser, and critic in the long process of library experience, course work, re- search, and writing that has culminated in this dissertation. The initial idea for the study arose out of my course with him; its development has takeD its shape largely out of our many subsequent discussions. He has always managed to combine searching criticism with the warmest personal encouragement. I am deeply grateful.
My thanks also go out to the other four members of my committee - Dr. Thomas E. Benner, Dr. Robert B. Downs, Dr. Rose B. Phelps, and Professor Ernest J. Reece - who were kind enough to read the lengthy initial draft; their suggestions and criticisms helped me avoid many errors. Dr. Harold Lancour also favored me with a thorough reading of the first draft.