Research Validity and Reliability

One of the questions researchers often ask is how their research can be both precise and of practical use to other researchers. To what extent can their results contribute to the area of science in which they work? To answer these questions researchers need to evaluate their work in relation to two criteria, that of valid­ity and of reliability.

To assess the overall validity of our research (and its reliability, as we will see later on), it is necessary to be sure of various more specific types of validity. These include construct validity, the validity of the measuring instrument, the internal validity of the research results and the external validity of those same results. These different kinds of validity concern both the research in its entirety (internal and external validity), and individual research components (the con­cepts or the measuring instruments used).

Although this chapter analyzes each of these different types of validity individually, it is not always possible to determine tests specific to each one.

More generally, there are two main concerns in relation to validity: assess­ing the relevance and the precision of research results, and assessing the extent to which we can generalize from these results. The first is a question of testing the validity of the construct and the measuring instrument, and the internal validity of the results – these three tests can in some cases involve very similar techniques. The extent to which we can generalize from research results is essentially a question of assessing the external validity of these results.

In assessing reliability we try to establish whether the study could be repeated by another researcher or at another time with the same results. This concept, like validity, involves two different levels: the reliability of the measuring instrument and the more overall reliability of the research. Even though these criteria have long been considered as applying only to quantitative research, the question of the validity and reliability of research applies as much to quali­tative as to quantitative work. There is an essential difference, however, in that we test quantitative research to assess its validity and reliability, whereas with qualitative research, rather than testing, we take precautions to improve validity and reliability.

There is no single method for testing the validity and reliability of a research project. Some techniques used for quantitative research can be inappropriate for qualitative research, which has led recent studies (Miles and Huberman, 1984a; Silverman, 1993) to propose validation techniques appropriate to a quali­tative methodology.

Source: Thietart Raymond-Alain et al. (2001), Doing Management Research: A Comprehensive Guide, SAGE Publications Ltd; 1 edition.