RESEARCH METHOD COHEN ok

TRIANGULATION 141
student’s problem-solving ability. The researcher
might observe the student working on a problem,
or might talk to the student about how she is
tackling the problem, or might ask the student
to write down how she tackled the problem.
Here the researcher has three different datacollecting
instruments – observation, interview
and documentation respectively. If the results
all agreed – concurred – that, according to given
criteria for problem-solving ability, the student
demonstrated a good ability to solve a problem,
then the researcher would be able to say with
greater confidence (validity) that the student was
good at problem-solving than if the researcher had
arrived at that judgement simply from using one
instrument.
Concurrent validity is very similar to its
partner – predictive validity – in its core concept
(i.e. agreement with a second measure); what
differentiates concurrent and predictive validity
is the absence of a time element in the former;
concurrence can be demonstrated simultaneously
with another instrument.
An important partner to concurrent validity,
which is also a bridge into later discussions of
reliability, is triangulation.
Triangulation
Triangulation may be defined as the use of two
or more methods of data collection in the study
of some aspect of human behaviour. The use of
multiple methods, or the multi-method approach
as it is sometimes called, contrasts with the
ubiquitous but generally more vulnerable singlemethod
approach that characterizes so much of
research in the social sciences. In its original
and literal sense, triangulation is a technique
of physical measurement: maritime navigators,
military strategists and surveyors, for example,
use (or used to use) several locational markers
in their endeavours to pinpoint a single spot
or objective. By analogy, triangular techniques
in the social sciences attempt to map out, or
explain more fully, the richness and complexity
of human behaviour by studying it from more
than one standpoint and, in so doing, by making
use of both quantitative and qualitative data.
Triangulation is a powerful way of demonstrating
concurrent validity, particularly in qualitative
research (Campbell and Fiske 1959).
The advantages of the multi-method approach
in social research are manifold and we examine
two of them. First, whereas the single observation
in fields such as medicine, chemistry and
physics normally yields sufficient and unambiguous
information on selected phenomena, it provides
only a limited view of the complexity of human
behaviour and of situations in which human
beings interact. It has been observed that as
research methods act as filters through which
the environment is selectively experienced, they
are never atheoretical or neutral in representing
the world of experience (Smith 1975). Exclusive
reliance on one method, therefore, may bias or
distort the researcher’s picture of the particular
slice of reality being investigated. The researcher
needs to be confident that the data generated
are not simply artefacts of one specific method
of collection (Lin 1976). Such confidence can
be achieved, as far as nomothetic research
is concerned, when different methods of data
collection yield substantially the same results.
(Where triangulation is used in interpretive
research to investigate different actors’ viewpoints,
the same method, e.g. accounts, will naturally
produce different sets of data.)
Further, the more the methods contrast with
each other, the greater the researcher’s confidence.
If, for example, the outcomes of a questionnaire
survey correspond to those of an observational
study of the same phenomena, the more the
researcher will be confident about the findings.
Or, more extreme, where the results of a rigorous
experimental investigation are replicated in,
say, a role-playing exercise, the researcher will
experience even greater assurance. If findings are
artefacts of method, then the use of contrasting
methods considerably reduces the chances of
any consistent findings being attributable to
similarities of method (Lin 1976).
We come now to a second advantage: some
theorists have been sharply critical of the limited
use to which existing methods of inquiry in the
Chapter 6