Focus groups are ubiquitous to the point that, for some, they have become the plain vanilla choice in our ever-eclectic assortment of flavors in research methods.  Yet, there are many (many) design considerations that complicate focus group research while directly impacting the credibility, analyzability, and, ultimately, usefulness of the outcomes.  One such consideration is discussed here.

Fundamental to the design of a focus group study is group composition.  More specifically, it must be determined the degree of homogeneity or heterogeneity the researcher wants represented by the group participants.  There is any number of questions the researcher needs to contemplate, such as the participants’:

• Age range and/or stage of life.
• Race.
• Ethnicity.
• Income or socioeconomic level.
• Level of education.
• Profession or job (including, job title).
• Community of residence.
• Group or organization association.
• Involvement, experience, or knowledge with the research topic, e.g., product usage activity, purchase behavior, level of expertise using new technology.

Whether or not – or the degree to which – group participants should be homogeneous in some or all characteristics has been at the center of debate for some years.  On the one hand, Grønkjaer, et al. (2011) claim that, “homogeneity in focus group construction is considered essential for group interaction and dynamics” and, in the same vein, Julius Sim has found in his health research that, “the more homogeneous the membership of the group, in terms of social background, level of education, knowledge, and experience, the more confident individual group members are likely to be in voicing their views.”  Even among strangers, there is a certain amount of comfort and safety in the group environment when the participants share key demographic characteristics and relevant experience.  A problem arises, however, when this comfortable, safe environment breeds a single-mindedness (or “groupthink”) that, without the tactics of a skillful moderator, can stifle divergent thinking and result in erroneous, one-sided interpretations of the findings.  Heterogeneity of group participants (e.g., including product users and nonusers in the same focus group) potentially heads off these problems by stimulating different points of view and a depth of understanding that comes from listening to participants “defend” their way of thinking (e.g., product preferences).  In addition to a heightened level of diversity, heterogeneous groups may also be a very pragmatic choice for the researcher who is working with limited time and financial resources, or whose target population for the research is confined to a very specific group (e.g., nurses working at a community hospital).

The answer to the question of whether group participants should be homogeneous or heterogeneous is “it depends.”  As a general rule, group participants should represent similar experiences with or knowledge of the research topic (e.g., experience using the Web to diagnose a health problem, weekly consumption of skim milk), but the need for “sameness” among participants on other parameters can fluctuate depending on the circumstance.  For example, homogeneity of age can be particularly important in non-Western countries where younger people may believe it is disrespectful to offer comments that differ from those stated by their elders.  Homogeneous groups are also typically important when investigating sensitive topics, such as drug use among teenagers, when a more mixed group of participants may not only choke the discussion but lead to a struggle for control among participants.  Homogeneity of gender, on the other hand, may or may not be important to the success (usefulness) of a focus group study.  To illustrate: A company conducting employee focus group research to explore employees’ attitudes toward recent shifts in management would conduct separate groups with men and women in order to discover how the underlying emotional response to new management differs between male and female employees.  In contrast, a focus group study among customers of the local electric utility company might benefit from including both men and women in the discussion where the varied reactions to the company’s bill inserts would serve to stimulate thinking and enrich the research findings.

Group composition is just one consideration when designing a focus group study.  There are many others.  Focus group research is anything but vanilla.