This overview from the Robert Wood Johnson Foundation provides a definition and outline of the reasons for using the confirming and disconfirming option.
"Identification of confirming and disconfirming case occurs after some portion of data collection and analysis has already been completed.
This is the process of selecting cases that either:
- serve as additional examples that lend further support, richness and depth to patterns emerging from data analysis (confirming cases)
- serve as examples that do not fit emergent patterns and allow the research team to evaluate rival explanations (disconfirming cases). This can help the research team understand and define the the limitations of research findings.
Why use this method?
Identifying confirming and disconfirming cases is a sampling strategy that occurs within the context of and in conjunction with other sampling strategies.
Researchers seek out confirming and disconfirming cases in order to develop a richer, more in depth understanding of a phenonmenon and to lend credibility to one's research account." (Cohen D, Crabtree B., 2006)
Sources
Cohen D, Crabtree B., (2006), Qualitative Research Guidelines Project. Retrieved from : http://www.qualres.org/HomeConf-3807.html
Related links
'Confirming and disconfirming cases' is referenced in:
Method