When I conduct a face-to-face qualitative study – whether it is a group discussion, in-depth interview, or in-situ ethnography – I am taking in much more than the behavior and attitudes of the research participants. Like most researchers, my scope goes way beyond the most vocal response to my questions or the behavior of store shoppers, but incorporates much more detail including the nuanced comments, the facial and body gestures, as well as the surrounding environment that may be impacting his or her thoughts or movements. So, while one of my face-to-face participants may tell me that he “just prefers” shopping at a competitor’s store for his hardware, I know from the entirety of clues throughout the interview that there is more to uncover which ultimately lands me on the real reason he avoids my client’s store – the unavailability of store credit. Likewise, the mobile research participant shopping at Walmart for coffeemakers may share her shopping experience via video and/or text but unintentionally omit certain components – e.g., the impact of competitive displays, product packaging, store lighting, surrounding shoppers – that would have been discovered in an in-person ethnography and contribute important insights.
Selection bias is inherent in nearly all research designs. At some level research participants are deciding what is important to communicate to the researcher and what is worthy of being ignored. From deciding whether to participate in a study, to the granularity of details they are willing to share, the participant – not the researcher – controls some measure of the research input. It is no wonder that many of the discussions concerning research design center on this issue, with survey researchers discussing at length the best method for sampling and selecting respondents (e.g., the next-birthday method in telephone studies), converting initial refusals, and effective probing techniques.
There is not much discussion on selection bias in qualitative research. One exception is an article by David Collier and James Mahoney* that addresses how selection bias undermines the validity of qualitative research. More focus on the issue of selection bias in qualitative research is warranted, particularly given the speed with which research designs today are evolving to keep up with new communication technology.
Mobile research is just one example of an increasingly popular qualitative research method. Mobile research provides for the first time a viable way to Read Full Text