What should a focus group composition be like? Which features participants should meet? The answer of these questions depends basicly on the population group under study and the aims of the research. However, a general rule should be followed. A certain homogeneity among participants is required. What does homogeneity mean? All members share something in common. It may be a common interest (music, sport, consumers of a specific product), origin (from the same city, country or neighboorhood) or whatever other feature. Like in a group of friends or gang, this reinforces participants as a group and, consequently, leads to a greater dialogue.
However, certain heterogeneity is also necessary. If you recruit very similar participants you run the risk that the group is not dynamic enough, i.e. everyone agrees and no dialogue is generated.If you are testing a product, you might recruit both consumers and non-consumers. If homogeneity guarantees group birth, heterogeneity does its growth. In other words, the different participant´s point of view enrich the dialogue. This is not a banal issue. The existence of “conflict” among participants is a key issue to make the best of a focus group. The point is to come across a debate-provoking variable or “turning point”. It is very clear in policy testing or electoral studies. Whenever a group is composed by both right and left participants, the debate is assured.
Finally, the composition of a focus group is normally organized in a table as bellow. There you can see a number of “homogeneity” and “heterogeneity” variables. In this example, the heterogeneity or turning point (breaking point) comes from the different brand consumption variable, while age and sex would reinforce participants as a group.