The development of behavior modification principles and procedures and
the ensuing research have had a dramatic impact on services for mentally
re- tarded persons. This book is the second edition of a volume that is
designed to update readers on some of these many developments. Although
many of the chapter titles and authors from the first edition remain
unchanged, we have added additional chapters to reflect new areas of
research. The book is thus a critical review of this literature and, as
such, provides essential and important notions about what we know and
what can be done to expand our current knowledge. The authors of the
chapters are all recognized experts who have been active in publishing
in the research areas they critique. As a result, they have a good
understanding of what are the major issues in the field. And because
they are also active in service provision to persons with identified
handicaps, their material will be especially useful to practitioners
and, it is hoped, to those_ professionals who are working in the field
in estab- lishing data-based treatments. One important change in the
field has concerned the terminology used to We are aware that persons
with mental retar- describe handicapped persons. dation are no longer
referred to as "the mentally retarded," and although no disrespect is
intended, for the sake of continuity the original title has been
retained on the advice of the publisher.