reliability and validity in qualitative research kirk and miller pdf

14 Convenience sampling is one of the most commonly used, yet one of the least appropriate, sampling strategies. Patton offers a succinct, clear, and comprehensive discussion of the various sampling strategies used in qualitative research. Readers of qualitative studies should look for sound reasoning in the description and justification of the strategies for selecting data sources. Selection criteria often evolve over the course of analysis, and investigators return repeatedly to the data to explore new cases or new perspectives. 14 This type of sampling usually aims to cover a range of potentially relevant social phenomena and perspectives from an appropriate array of data sources. The logic and power of purposeful sampling lie in selecting information rich cases (participants or settings) for indepth study to illuminate the questions of interest.

Most qualitative studies use purposeful (or purposive) sampling, a conscious selection of a small number of data sources that meet particular criteria. In quantitative studies, the ideal sampling standard is random sampling.

The emergent nature of qualitative research that results from the interaction between data collection and data analysis requires that investigators not prespecify a sample for data collection in strict terms, lest important data sources be overlooked. WAS THE METHOD OF SAMPLING APPROPRIATE FOR THE RESEARCH QUESTION AND DESIGN? 21 Although the specific criteria for proper application of each methodological approach vary somewhat, there are sufficient similarities among the approaches to discuss them in general. A critical analysis of a qualitative study considers the “fit” of the research question with the qualitative method used in the study. Qualitative approaches arise from specific disciplines and are influenced by theoretical perspectives within those disciplines. 20 References to articles that describe these different qualitative research approaches in greater detail are listed in the online version of this Users’ guide. 18 A grounded theory approach is used to discover the social-psychological processes inherent in a phenomenon, 19 whereas a phenomenological approach is used to gain a deeper understanding of the nature or meaning of the everyday “lived” experiences of people. Traditional ethnography seeks to learn about culture from the people who actually live in that culture. Other approaches include case studies, narrative research, and historical research. 17 Common approaches in published healthcare research include ethnography, grounded theory, and phenomenology.

More than 40 unique approaches to qualitative research methods have been identified. IS THE DESIGN APPROPRIATE FOR THE RESEARCH QUESTION?

Reliability and validity in qualitative research kirk and miller pdf