Morgan, David L. (2004)
S. N. Hesse-Biber and P. Leavy (Eds.), Approaches to Qualitative Research: A Reader on Theory and Practice, pp. 263-285. New York, NY: Oxford University Press
Written by a long-time authority on focus group, presents a brief history of focus group application up to, and including, information on the variety of current uses across many disciplines. Great section on the uses of focus groups in combination with other methods with a full compare/contrast discussion. Finally, goes into the specifics on ‘how to’ plan and conduct effective group data collection.
My own preference (Morgan, 1996) is for a more inclusive approach that broadly defines focus groups as a research technique that collects data through group interaction on a topic determined by the researcher. In essence, it is the researcher's interest that provides the focus, whereas the data themselves come from the group interaction.
One reason for favoring an inclusive approach is that the exclusive approaches do not really exclude very much. Other than focus groups, the primary categories of group interviews in the existing typologies are things that are manifestly different from focus groups. On the one hand, there are nominal groups and Delphi groups (Stewart & Shamdasani, 1990), which do not involve actual group interaction. On the other hand, there is the observation of naturally occurring groups, which typically do not involve the researcher in determining the topic of discussion. Thus, little is gained by excluding these categories of data collection because they already fall outside the broad definition of focus groups offered here.
Among the more specific criteria that could be used to distinguish focus groups from other types of group interviews, both Frey and Fontana (1989) and Khan and Manderson (1992) assert that focus groups are more formal. In particular, they argue that focus groups are likely to involve inviting participants to the discussion and they also stress the distinctive role of the moderator. Although there is no doubt that group interviews vary along a continuum from more formally structured interaction to more informal gatherings, I do not believe it is possible to draw a line between formal and informal group interviews in a way that defines some as focus groups and others as something else. Instead, I find it more useful to think that the degree of formal structure in a focus group is a decision that the research makes according to the specific purposes of the research project. In particular, the use of either a more formal or a less formal approach will depend on the researcher's goals, the nature of the research setting, and the likely reaction of the participants to the research topic.
Among the other criteria that have been offered as distinguishing features of focus groups are their size and the use of specialized facilities for the interview (McQuarrie, 1996). Again, however, these supposedly exclusive criteria are mostly a matter of degree. Who is to say when a group is too large or too small to be called a focus group or when a setting is too casual to qualify? Rather than generate pointless debates about what is or is not a focus group, I prefer to treat focus groups as a "broad umbrella" or "big tent" that can include many different variations. Of course, this approach requires researchers to make choices about doing focus groups one way rather than another. Fortunately, this need to make explicit decisions about data collection strategies is a familiar concern to social scientists, and it comes under the heading of "research design." As social scientists have gained increasing experience with focus groups, we also have produced insights into the situations in which different research designs are either more or less likely to be effective (e.g., Krueger, 1993; Morgan, 1992.a, 1995).