Determination of Validity, Reliability and Sample Size in Qualitative Studies
How to ensure the validity and reliability issues in research with increasing evidence based studies began to show up. Validity, reliability and power analysis in quantitative studies were demonstrated by numerical indicators. However, in qualitative studies there is not quantitative data to prove it and it is difficult to prove validity, reliability and power analysis. Therefore, the aim of this review is to show how to ensure the validity and reliability in qualitative studies and how to determine the sample size with power analysis. Reliability and validity in qualitative research is considered to be different from the quantitative study. There are number of strategies that qualitative researchers can be used to increase credibility of findings. Guba and Lincoln pointed out that trustworthiness should be in qualitative research rather than the validity and reliability. Guba and Lincoln collected trustworthiness criteria under four main headings such as credibility, dependability, confirmability and transferability. The qualitative power analysis shows to put forward an effective of the subject with enough sample size. The credibility of the results is considered to be one of the most significant scientific researches. To take all measures necessary to demonstrate the credibility of the work of researchers and qualitative research process and data in a clear and detailed description of a form, make enough sample size selection is important. It is expected that this review will facilitate the decision making processes of researchers and evaluate qualitative study.