Status of the Field Today 655Society in 1949. In 1957 both Division 21 of the APA (then
known as the Society of Engineering Psychologists, and now
known as the Division of Applied Experimental and Engi-
neering Psychology) and the Human Factors Society (now
known as the Human Factors and Ergonomics Society) came
into existence. There now are numerous associations and so-
cieties of a similar sort in several countries, as well as orga-
nizations and journals, that represent more focused interests
within applied experimental psychology broadly defined.
Although researchers who affiliate with these organizations
continue to focus attention on implications of human capa-
bilities and limitations for system and equipment design and
operation, interests have broadened into process control,
transportation systems, health systems, human-computer
interaction (HCI), design for the aging population, and many
other areas.
During the 1960s and 1970s the most significant stimuli to
further growth in the field in the United States were associated
with initiatives of various government regulatory organiza-
tions. Many of these initiatives were stimulated by one or
more levels of advocacy from the public sector. For example,
Ralph Nader’s 1965 bookUnsafe at Any Speedand related
advocacy led to the establishment of the National Highway
Safety Bureau (NHSB) to carry out safety programs under the
National Traffic and Motor Vehicle Safety Act of 1966 and the
Highway Safety Act of 1966. In 1970 the National Highway
Transportation Safety Administration was created as the
successor to the NHSB. The critical incident at the Three
Mile Island nuclear power generation plant in 1979 mar-
shaled the public support that led the Nuclear Regulatory
Commission to establish a Division of Human Factors Safety
in 1980. These agencies, which focused predominantly on is-
sues of safety, recognized that accidents are seldom exclu-
sively physical in origin—that they almost always involve
human error and that an understanding of human sensory, cog-
nitive, and motor processes is essential to reducing that error.
In the 1980s and 1990s, although safety was still an
important focus, the emphasis shifted somewhat to questions
of ease of use of products of technology, and increased atten-
tion was given to the user interface in computer software de-
sign. Computers have become ubiquitous in the workplace
and in the home. Not only are desktop computers common-
place, but most modern appliances and workplace systems,
from videocassette recorders and hospital patient monitors to
automated teller machines and vehicle navigation systems,
also have one or more computers embedded in them some-
where. Usability has become a major objective of effective
software design and evaluation, and many of the methods of
experimental psychology have been adapted to respond to
this need.
STATUS OF THE FIELD TODAYHow should we think of applied experimental psychology
as it exists today? As a discipline (like high-energy physics
or biochemistry)? An occupational specialty (like forensic
psychology or vocational counseling)? A topical focus (like
vision or working memory)? A methodology (like eye-
movement tracking or evoked-potential recording)? We think
it is none of these, but rather a domain of psychological re-
search defined as experimentation with a practical purpose; it
encompasses that work within experimental psychology that
is motivated to a significant degree by practical concerns. We
say “to a significant degree” because we do not wish to sug-
gest that it is driven only by practical concerns; as already
noted, we believe that much of the best applied work is moti-
vated by, and contributes substantively to, both practical and
theoretical interests.Practical but Not AtheoreticalThe last point deserves emphasis. Sometimes applied work is
assumed necessarily to be atheoretical. We take issue with
this view. It is possible for work to be motivated by the desire
to answer an immediate practical question and to be athe-
oretical, and it is possible for work to be motivated by a
purely theoretical question that has no obvious relevance to
any real-world problem; but it is not essential that practical
work be atheoretical or that theoretical work be divorced
from applications.
Of special relevance to the focus of this chapter are nu-
merous examples of theoretical ideas and constructs that
have been put forth and developed by investigators who were
keenly interested in practical problems and who were moti-
vated to help solve them. Among the names that come imme-
diately to mind in this regard are Frederic Bartlett (1932,
1943, 1948), Paul Fitts (1951, 1954; Fitts & Seeger, 1953),
and Donald Broadbent (1957, 1958, 1971). These and many
other investigators who could be mentioned did work that si-
multaneously addressed theoretical and practical interests.
Among the theoretical ideas that have been closely associ-
ated with applied work—sometimes guiding that work and
sometimes being informed by it—are theories of human
motor skills, information theory (and communications theory
more generally), detection and decision theory, and game
theory.An Interdisciplinary FieldMuch applied experimentation is interdisciplinary in the
sense that addressing applied problems in specific domains