Guba (1981) proposes four criteria that should be considered by qualitative researchers in pursuit of trustworthiness:
a) Credibility (in preference to internal validity): One of the key criteria addressed by positivist researchers is that of internal validity, in which they seek to ensure that their study measures or tests what is actually intended. According to Merriam, the qualitative investigator’s equivalent concept, i.e. credibility, deals with the question,
“How congruent are the findings with reality?”
Some strategies to assure credibility are:
- Adoption of appropriate, well recognised research methods
- Triangulation via use of different methods, different informants, different sites, and moments.
- Tactics to help ensure honesty in informants
- Debriefing sessions between researchers
- Description of background, qualifications and experience of the researcher
- Member checks of data collected and interpretations/theories formed
- Thick description of phenomenon under scrutiny
- Examination of previous research to frame findings
b) Transferability (in preference to external validity/generalizability): External validity “is concerned with the extent to which the findings of one study can be applied to other situations”. In positivist work, the concern often lies in demonstrating that the results of the work at hand can be applied to a wider population. Since the findings of a qualitative project are specific to a small number of particular environments and individuals, it is difficult to demonstrate that the findings and conclusions are applicable to othersituations and populations. Because of that we use “Naturalistic Generalization” (Stake, 2005). Naturalistic generalization is a process where readers gain insight by reflecting on the details and descriptions presented in case studies. As readers recognize similarities in case study details and find descriptions that resonate with their own experiences; they consider whether their situations are similar enough to warrant generalizations.
Naturalistic generalization invites readers to apply ideas from the natural and in-depth depictions presented in case studies to personal contexts.
Some strategies to assure Transferability are:
-Provision of background data to establish context of study and detailed description of phenomenon in question to allow comparisons to be made
c) Dependability (in preference to reliability): In addressing the issue of reliability, the positivist employs techniques to show that, if the work
were repeated, in the same context, with the same methods and with the same participants, similar results would be obtained.
In order to address dependability in Qualitative research, the processes within the study should be reported in detail, thereby enabling a future researcher to repeat the work, if not necessarily to gain the same results. Thus, the research design may be viewed as a detailed “prototype model”.
Some strategies to assure Dependability are:
-Employment of “overlapping methods”
-In-depth methodological description to allow study to be repeated
d) Confirmability (in preference to objectivity): Objectivity in science is associated with the use of instruments that are not dependent on human skill and perception.The concept of confirmability is the qualitative investigator’s comparable concern to objectivity. Here steps must be taken to help ensure as far as possible that the work’s findings are the result of the experiences and ideas of the informants, rather than the characteristics and
preferences of the researcher.
Some strategies to assure Confirmability are:
-Triangulation to reduce effect of investigator bias
-Admission of researcher’s beliefs and assumptions
-Recognition of defects in study’s methods and their potential effects
-In-depth methodological description to allow integrity of research results to be scrutinized
-Use of diagrams to demonstrate “audit trail”
The following article addresses these issues really well:
Shenton, A. K. (2004). Strategies for ensuring trustworthiness in qualitative research projects. Education For Information, 22(2), 63-75.
And here the reference to Guba´s work:
E.G. Guba, Criteria for assessing the trustworthiness of naturalistic inquiries, Educational Communication and Technology Journal 29 (1981), 75–91.