Rigor refers to assessing quality and accuracy of research processes and conclusions. Rigor of a research involves the concepts of credibility (reliability) and validity. First major criterion for rigor in qualitative research is “internal validity” (trustworthiness), which means questioning the true value of the research for trustworthiness and to clarify the question “Does this research have a valid value?” Answering the questions below could be advised to establish trustworthiness for a given research:

• Are the findings of the research significant/ meaningful?
• Are the findings trustworthy for the participants and readers?
• Is there a genuine picture of the case we have been analyzing or trying to figure out?
• Are the descriptions of cases comprehensive and meaningful enough?
  Are the patterns built by the findings coherent and holistic?
• Do different data sources provide common or overlapping findings and results?

Another important criterion for rigor in qualitative research is “external validity” (transferability). This refers to precise definition or explanation of the area that findings can be generalized to. It is not a generalization based on numbers as in quantitative studies, but an analytic generalization in terms of similar units, places, or cases.