656 Psychological Experimentation Addressing Practical Concerns
requires knowledge of those domains. If, for example, one
wishes to do research on teaching or learning for the express
purpose of helping to increase the effectiveness of classroom
instruction, one must know more than a little about education
from a practitioner’s point of view. Or if one wants to work
on the objective of decreasing the frequency of human error
in the operating room or in the delivery of medical services
more generally, one needs to know a lot—or to work with
someone who knows a lot—about medical procedures and
systems.
Many psychological researchers who work in highly
applied areas, such as the human factors of aviation, nuclear
power plant control, or manufacturing, have training both
in psychology and in their area of application. Others work
as members of research teams that depend on domain spe-
cialists to contribute the domain-specific knowledge to the
operation, but even here the psychologist is likely to need a
more-than-passing acquaintance with the relevant disciplines
in order to ensure a smoothly functioning and productive
team endeavor.
Laboratory and Field Experimentation
Experimentation, as we are using the term, includes both lab-
oratory and field studies. People doing applied research are
keenly aware of the considerable differences that typically
characterize laboratory and field work. Variables are easier to
control in the laboratory than in the field; as a consequence,
the results of laboratory experiments typically are easier to
interpret. However, the increased control usually comes at
the expense of less realism than one has in operational real-
world situations, so while the laboratory results may be eas-
ier to interpret, they are likely to be harder to apply without
qualification to the real-world situations of interest.
A strategy that has been recommended for applied
research involves both laboratory and field research. Hy-
potheses can be tested in a preliminary fashion in simplified
or abstracted laboratory simulations of real-world situations,
perhaps using students as participants, and then the findings
can be checked with people functioning in their normal real-
world contexts. This approach is illustrated by the work of
Gopher, Weil, and Bareket (1994) in checking the extent to
which effects of training with a simulation of certain aspects
of flight control transfer to performance in an actual flight sit-
uation. Unfortunately, too often only the first step is taken,
and the assumption is made that the results obtained will
transfer to the operational situations of interest. We believe
that the development of a trustworthy store of psychological
knowledge that can be applied in confidence to real-world
problems requires a continuing interplay between laboratory
and field experimentation where what is learned in each con-
text is informing further work in the other, and theory is being
refined by the outcomes of both types of research.Closely Related DisciplinesDefined as psychological experimentation that is explicitly
addressed to practical concerns, applied experimental psy-
chology overlaps considerably with several other disciplines.
Most obviously, it has much in common with human-factors
psychology (which for purposes of this chapter can be con-
sidered synonymous with ergonomics or engineering psy-
chology, although for some purposes somewhat different
connotations are given to these terms; Nickerson, 1999; Pew,
2000; Wogalter, Hancock, & Dempsey, 1998). It intersects
also with many subfields in psychology that are defined
by a focus on an area of application, such as organizational/
industrial psychology, military psychology, aviation psychol-
ogy, forensic psychology, consumer psychology, and the psy-
chology of aging, among several others. Researchers in each
of these and other subfields conduct experimental studies
addressed to practical questions of special interest to people
involved in these areas and hence provide many examples of
applied experimental psychology.EmploymentThe kinds of settings in which applied experimental psychol-
ogists work are as varied as are the fields of activity. Many
applied experimentalists work in universities, and their work
is frequently associated with institutes or other organizations
that specialize in applied work, perhaps with a specific focus,
such as transportation, education, aging, disabilities, or com-
puter technology. Major employers of experimentalists are
the various branches and research laboratories of the federal
government. Notable among these are the laboratories of
the military services, the National Aeronautics and Space
Administration, the Department of Transportation, and the
National Institutes of Health.
Several for-profit and nonprofit companies provide op-
portunities for applied experimentalists. These include the
American Institutes of Research, Anacapa Sciences, and
CHI Systems. Many large corporations have human-factors
groups that either work on their own in-house research and
development programs or on systems-development projects
done under contract for the government or other organiza-
tions. Boeing and Lockheed-Martin in the aerospace industry
and Ford and General Motors in the automotive industry are
examples of such companies in the United States. Product-
development projects may involve experimentation during