HYPOTHESES: CRAFTING TESTABLE PREDICTIONS

Although the diffusion of responsibility theory seems to make sense, it represented
only the beginning of Latané and Darley’s investigative process. Their next step was
to devise a way to test their theory. To do this, they needed to create a hypothesis.
A hypothesis is a prediction stated in a way that allows it to be tested. Hypotheses
stem from theories; they help test the underlying soundness of theories.
In the same way that we develop our own broad theories about the world, we
also construct hypotheses about events and behavior in our lives. Those hypotheses
can range from trivialities (such as why our English teacher wears those weird shirts)
to more meaningful matters (such as what is the best way to study for a test).
Although we rarely test these hypotheses systematically, we do try to determine
whether they are right. Perhaps we try comparing two strategies: cramming the night
before an exam versus spreading out our study over several nights. By assessing
which approach yields better test performance, we have created a way to compare
and even measure the two strategies.
A hypothesis must be restated in a way that will allow it to be tested, which
involves creating an operational definition. An operational definition is the translation
of a hypothesis into specific, testable procedures that can be measured and
observed.
There is no single way to go about devising an operational definition for a
hypothesis; it depends on logic, the equipment and facilities available, the psychological
perspective being employed, and ultimately, the creativity of the researcher.
For example, one researcher might develop a hypothesis that uses “an increase in
heart rate” as an operational definition of “fear.” In contrast, another psychologist’s
an operational definition of “fear” might be written responses to the question “How
much fear are you experiencing at this moment?”
Latané and Darley’s hypothesis was a straightforward prediction from their more
general theory of diffusion of responsibility: The more people who witness an emergency
situation, the less likely it is that help will be given to a victim. They could,
of course, have chosen another hypothesis (try to think of one!), but their initial
formulation seemed to offer the most direct explanation of the theory.
Psychologists rely on formal theories and hypotheses for many reasons. For one
thing, theories and hypotheses allow them to make sense of unorganized, separate
observations and bits of information by permitting them to place the pieces within
a coherent framework. In addition, theories and hypotheses offer psychologists the
opportunity to move beyond known facts and make deductions about unexplained
phenomena and develop ideas for future investigation.
In short, the scientific method, with its emphasis on theories and hypotheses,
helps psychologists pose appropriate questions. With properly stated questions in
hand, psychologists then can choose from a variety of research methods to find
answers.