Group Size & Number

  • To produce valid results, it usually involves more than one focus group. The usual number of group varies from 3 to 8, and it depends on your research questions and topic.
  • A group of 6 to 8 members is a good size to acquire greater depth of data and participants’ engagement. There are situations that a larger group would be more suitable.  For instance, a group of 10 to 12 participants may be suitable for a marketing research, which aims to capture as many different opinions as possible in a short period of time.
  • However, a group larger than 7 or 8 participants is harder to manage (Carey and Asbury, 2012).
  • Researchers also need to consider the number of questions and the length of the entire discussion for each group. The number of questions or themes to be discussed should not be too much so that each participant has enough speaking time.

Morgan (1998:73-5) has suggested the followings when forming groups of different sizes:

  • Smaller groups:
  1. When participants have a high level of involvement with the topic
  2. When participants are emotionally caught up in the topic
  3. When participants are experts or know a lot about the topic
  4. When the topic is controversial
  5. When the topic is complex
  6. When the goal is to hear detailed stories and personal accounts
  7. When recruitment factors limit other options
  • Larger groups
  1. When participants have a low level of involvement with the topic
  2. When the goal is to hear numerous brief suggestions, as in brainstorming
  3. When recruitment factors limit other options