The following is a modified excerpt from Applied Qualitative Research Design: A Total Quality Framework Approach (Roller & Lavrakas, 2015, pp. 130-131).
Qualitative researchers are routinely faced with the decision of how many in-depth interviews (IDIs) or focus group discussions to conduct. This decision often revolves around time-cost-benefit trade-off considerations fueled by the tension between neither wanting to conduct too many nor too few IDIs or focus groups.
When it comes to the focus group method, the decision of how many group discussions to conduct is based on any number of factors and will vary depending on the situation for each study. However, a few of the critical factors that the prudent researcher will think about when considering the number of discussions at the outset for any focus group study are the:
- Geographic range of the target population, e.g., whether the target population for in-person groups is located in one city or spread across the U.S.
- Depth of the discussions, i.e., the number of topics/issues and questions expected to be covered to satisfy research objectives. For example, fewer group discussions may be necessary if the primary research objective is to learn mothers’ preferences for shelf-stable baby food, while a greater number of groups may be needed if the objective is to understand mothers’ preferences across all types of baby food and, specifically, to investigate the priority they place on nutritional and organic foods.
- Homogeneity or heterogeneity of the group participants. Using the example above, more groups will be required if the mothers of interest range in age from 25-40 years as well as in income level and if there is reason to believe that attitudes and behavior vary across these demographic characteristics.
- Variation in results that is expected to occur across the different focus groups that will be conducted. If there is little variation expected from one group to another (e.g., if group participants are highly homogeneous, or the attitudes among participants in New York are not expected to be different than those in Dallas), then only a few focus groups may suffice. If there is a great deal of variation expected, then many focus groups will be required to fully measure the range of experiences, attitudes, and knowledge the participants will have to impart in the discussions.
- Project schedule and amount of available time to complete the study.
- Research budget that is available to fund the study.
It is this assortment of factors that cause qualitative researchers to generally disagree on the optimal number of Read Full Text
The RDR post on February 20, 2013 talked about focus group research and how it is anything but a “plain vanilla” research method in terms of design considerations. To illustrate, the post discussed the issue of group composition; specifically, the “homogeneity or heterogeneity the researcher wants represented by the group participants.” Another important design consideration in face-to-face group discussions centers on the social context and especially the impact that participants’ interactions have on the discussion and, consequently, the research outcomes. This is a pretty obvious facet of the focus group method yet, surprisingly, it is largely ignored in the analysis and reporting of group research. Researchers and non-researchers alike complain about the disruptive effect of “dominators” (outspoken group participants who assert their opinions without regard to others), the refusal of “passive” participants to speak their minds, and/or participants talking over each other (making it impossible to hear/follow the discussion) but focus group reports typically fail to discuss these interactions and the role they played in the final analysis.
The good news is that some researchers have given extensive thought to the interaction effect in focus group research and have promoted the idea that this effect needs to be a considered element in the study design. One example is Lehoux, Poland, and Daudelin (2006) who have proposed a “template” by which qualitative researchers can think about, not only how group interaction impacts the group process but also, how participants’ interaction dictates the learning or knowledge the researcher takes away from the discussion. The Lehoux, et al. template consists of specific questions the researcher should address during the analysis phase. For instance, group-process questions include “What types of interactions occur among participants?”, “Which participants dominate the discussion?”, and “How does this affect the contribution of other participants?” The knowledge-content questions ask things like “What do dominant and passive positions reveal about the topic at hand?” and “What types of knowledge claims are endorsed and/or challenged by participants?”
The credibility and ultimate usefulness of our focus group research depends on a thorough and honest appreciation for what goes on in the field. The analysis and reporting of the “interactional events” that guided the discussions in our group research is the obligation of all researchers. Otherwise, what really went on in our discussions is some kind of secret we harbor, leaving the users of our research – and the researchers themselves – blinded to the true outcomes. Like a kaleidoscope, our understanding of what we “see” from our focus group research depends on how we account for the interactions taking place, and how each dominant and passive piece plays a role in creating the final effect.