12 Part I Introduction
longer able to generate additional research or to explain related research data, it
loses its usefulness and is set aside in favor of a more useful one.
In addition to sparking research and explaining research data, a useful theory
must lend itself to confirmation or disconfirmation, provide the practitioner with a
guide to action, be consistent with itself, and be as simple as possible. Therefore, we
have evaluated each of the theories presented in this book on the basis of six criteria:
A useful theory (1) generates research, (2) is falsifiable, (3) organizes data, (4) guides
action, (5) is internally consistent, and (6) is parsimonious.Generates Research
The most important criterion of a useful theory is its ability to stimulate and guide
further research. Without an adequate theory to point the way, many of science’s
present empirical findings would have remained undiscovered. In astronomy, for
example, the planet Neptune was discovered because the theory of motion gener-
ated the hypothesis that the irregularity in the path of Uranus must be caused by
the presence of another planet. Useful theory provided astronomers with a road
map that guided their search for and discovery of the new planet.
A useful theory will generate two different kinds of research: descriptive
research and hypothesis testing. Descriptive research, which can expand an exist-
ing theory, is concerned with the measurement, labeling, and categorization of the
units employed in theory building. Descriptive research has a symbiotic relation-
ship with theory. On one hand, it provides the building blocks for the theory, and
on the other, it receives its impetus from the dynamic, expanding theory. The more
useful the theory, the more research generated by it; the greater the amount of
descriptive research, the more complete the theory.
The second kind of research generated by a useful theory, hypothesis testing,
leads to an indirect verification of the usefulness of the theory. As we have noted,
a useful theory will generate many hypotheses that, when tested, add to a database
that may reshape and enlarge the theory. (Refer again to Figure 1.1.)Is Falsifiable
A theory must also be evaluated on its ability to be confirmed or disconfirmed;
that is, it must be falsifiable. To be falsifiable, a theory must be precise enough
to suggest research that may either support or fail to support its major tenets. If a
theory is so vague and nebulous that both positive and negative research results
can be interpreted as support, then that theory is not falsifiable and ceases to be
useful. Falsifiability, however, is not the same as false; it simply means that neg-
ative research results will refute the theory and force the theorist to either discard
it or modify it.
A falsifiable theory is accountable to experimental results. Figure 1.1 depicts
a circular and mutually reinforcing connection between theory and research; each
forms a basis for the other. Science is distinguished from nonscience by its ability
to reject ideas that are not supported empirically even though they seem logical
and rational. For example, Aristotle used logic to argue that lighter bodies fall at
slower rates than heavier bodies. Although his argument may have agreed with
“common sense,” it had one problem: It was empirically wrong.