requirement, but from the viewpoint of attention rather than need.
Personality traits may be seen as a form of capability, but from the
viewpoint of tendency rather than skill. More theoretical develop-
ment in PEC theory is required to incorporate these two important
classes of person variables.
Measurement of PEC Variables
A theory cannot be applied in practice or research if its variables
cannot be measured. The variables of PEC theory can be measured
in a number of ways, not just the way they were measured in the
Work Adjustment Project and not just by using the Minnesota in-
struments (even if, modesty aside, these instruments are as good as
any. For detail on the Minnesota instruments, see Dawis & Lofquist,
1984, and the Minnesota Studies in Vocational Rehabilitationseries).
The discussion that follows will elaborate on these points and, for
convenience, will focus on P measurement.
Skills
We begin with skills because the technology of skill measure-
ment dates back to the beginnings of scientific psychology. The
measurement of human skills, especially cognitive skills, was sci-
entific psychology’s first problem. It gave rise to both psychophysics
and psychometrics, and to psychological testing as well. Even to-
day, much of psychology is engaged in the assessment and measure-
ment of human capabilities, that is, human skills.
With the technology of skill measurement, we can in principle
develop a measure of practically any human skill. However, the
problem is that there are many human skills, almost too many to
measure (not to mention the fact that new human skills are evolv-
ing all the time). Therefore, the assessment of all the skills a person
has is not practicable.
Fortunately, there is a way to “summarize” or “compress” scores
on many variables. Factor theory (factor analysis theory) allows us
PERSON-ENVIRONMENT-CORRESPONDENCE THEORY 443