Reliability and Validity in Qualitative Studies
By Marilyn Simon and Jim Goes
Discussions about reliability and validity are ubiquitous in quantitative research, but these essential elements of confidence in the research often receive less attention and scrutiny in qualitative studies. In qualitative research, validity–or trustworthiness– and reliability—or consistency– are discussed in terms of the credibility, transferability, dependability, and confirmability of the instrumentation and results of the study.
It is important to understand that dependability is to qualitative research as reliability is to quantitative research. There must be credibility in order to have dependability. The qualitative researcher needs to explain how dependability and credibility are assured and in the research methodology and documented in the data that are collected.
To assure credibility (internal validity) you can describe appropriate strategies such as triangulation, prolonged contact, member checks, saturation, reflexivity, and peer review. To establish transferability (external validity) you can explore appropriate strategies such as “thick descriptions” (Geertz, 1973), and variation in participant selection. Dependability (the qualitative counterpart to reliability) can be established through audit trails and triangulation. Confirmability (the qualitative counterpart to objectivity) is established through reflexivity or intra- or inter-coder reliability, where applicable.
Providing participants a copy of the transcribed notes from audio recordings enables them to review detailed interview responses (member checking), and verify the interpretive accuracy. This increases reliability (Carlson, 2010). Verifying participants’ answers, response uniformity, and within method triangulation (Casey & Murphy, 2009) provide a construct to test instrument reliability related to the interview questions. Similarity in responses among the participants throughout the interview corroborates the research instrument and the accuracy of responses (Stevenson & Mahmut, 2013). Harvey (2014) has suggested a continuous member-checking loop as part of the reliability process.
Validity in qualitative research indicates consistency and trustworthiness regarding activities and events associated with the phenomenon as signified by the study results explored in the research (Golafshani, 2003). Survey tools like our VREP (see: www.dissertationrecipes.com ) allow experts to assure validity of researcher designed instruments. Validity and reliability increase transparency and decrease opportunities to insert researcher bias in qualitative research (Singh, 2014). The researcher must ensure reliability and validity of the study based on the ability to maintain neutrality, and trustworthiness (Golafshani, 2003). Establishing validity can present challenges for qualitative researchers (Cho & Trent, 2006). However, experts agree on the need to assure validity, credibility, and reliability in qualitative studies (Konradsen, Kirkevold, & Olson, 2013). Nevertheless, experts disagree on how researchers adhere to quality criteria within their research projects (Ali & Yusof, 2012).
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Geertz, C. (1973). Thick description: Toward an interpretive theory of culture. The interpretation of cultures: Selected essays. New York: Basic Books.
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