In the social sciences and urban planning, focus groups allow interviewers to study people in a more natural setting than a one-to-one interview. In combination with participant observation, they can be used for gaining access to various cultural and social groups, selecting sites to study, sampling those sites, and raising unexpected issues for exploration. Focus groups have a high apparent validity, since the idea is easy to understand, the results are believable. Also, they are low in cost, one can get results relatively quickly, and they can increase the sample size of a study, since the interviewer is able to talk with several people at once.

However, focus groups also have disadvantages: the researcher has less control over a group than a one-on-one interview, and thus time can be lost on issues irrelevant to the topic; the data are tough to analyse because the talking is in reaction to the comments of other group members; interviewers need to be highly trained; and groups are quite variable and can be difficult to gather together.

1. This definition extracted from the Wikipedia definition for focus groups (accessed 28 December 2006) [disclaimer].