How valid and reliable are qualitative studies?

Qualitative work has been identified in some quarters as weak, without rigour, subjective and of little use. For an interesting discussion on this see http://www.biomedcentral.com/1471-2288/9/52. In contrast, quantitative research, which aims to delineate phenomena into measurable categories, generalizable to other populations is often viewed as superior. In quantitative research standardised measures are often used in an attempt to collect varying perspectives and experiences of people. For example a list of behaviours may be rated by an observer using a predetermined scale as an instrument in the research to collect data. This is all well and good but once the tool has been used to collect the numbered answers how do we know the measuring instrument was able to measure what it was supposed to measure. Also if we are carrying out a randomised controlled trial of a drug therapy and the drug is not taken regularly by participants in the trial how do we determine why that was if managing an experiment using only quantitative methods? Sometimes we need to ask questions and analyse answers in words in order to understand human experience. As Eisner says a well-executed qualitative study can help us “understand a situation that would otherwise be enigmatic or confusing” (Eisner, 1991, p. 58). The enlightened eye: Qualitative inquiry and the enhancement of educational practice. New York, NY: Macmillan Publishing Company.

But back to the issue of validity and reliability – how do we ensure qualitative studies are of high calibre and we can trust the findings presented. How do we know they are trustworthy? Lincoln and Guba are two well-known and very experienced qualitative researchers who have guided the qualitative debate over many years. See Lincoln & Guba (1985) Naturalistic Inquiry, for further discussion

They discuss a variety of ways to enhance qualitative work and each should be easily identified in any good study:

Credibility – this is viewed as one of the most important constructs that assists in establishing trustworthiness of research. Credibility means we have confidence in the findings of the study and it can be established in a number of ways

  1. prolonged engagement in the setting with a range of people.
  2. Triangulation where multiple data sources are used to produce understanding. Previously triangulation has been viewed as a method for testing for validity.  This has become controversial as it assumes that it is always possible to make sense of different accounts but this is very difficult to do.
  3. Peer debriefing defined as:

“a process of exposing oneself to a disinterested peer in a manner paralleling an analytical session and for the purpose of exploring aspects of the inquiry that might otherwise remain only implicit within the inquirer’s mind” (Lincoln & Guba, 1985, p. 308)

Someone who helps debrief can assist the researcher to uncover taken for granted biases, or assumptions and deal with these.

  1. Member checking – when data and conclusions are tested with members of those groups from whom the data were originally obtained. Again this is controversial as it relies on the assumption of a fixed truth or reality that is presented by the researcher and confirmed by a respondent

Transferability – this means the findings have applicability in other contexts. Giving a ‘thick description’ of a phenomenon in sufficient detail allows readers to evaluate the extent to which the conclusions drawn are transferable to their settings and people.

Dependability – this is concerned with demonstrating that the findings are consistent and could be repeated. External audits can help with this where a researcher not involved in the research examines the processes and findings of the research study in order to evaluate accuracy and if the findings and conclusions are supported by the data.

Confirmability – this is the extent to which the findings of a study are shaped on what has been reported by participants and not researcher bias. Reflexivity is an important concept here and involves the researcher attending to how knowledge has been constructed and the effect of the research on the researcher and the researcher on the research.

In trying to identify valid and reliable qualitative research studies there are a number of tools which can be used and are recommended, particularly for the novice researcher – the websites below should help:

http://www.casp-uk.net/

http://www.casp-uk.net/#!casp-tools-checklists/c18f8

http://www.huttvalleydhb.org.nz/content/e2d00f37-f0ed-4c59-b2bb-05254f2dec9b.cmr

There is a also a great utube video here: http://www.youtube.com/watch?v=izaIWCWA5Rc

The CASP tool is a good place to start. It includes 10 questions starting with ‘Was there a clear aim to the research’. Best of luck in finding the best qualitative research to inform your practice. Also look out for a short piece I will be writing in the New Year on validity and reliability for Evidence Based Nursing

 

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