Many believe that asking lots of people questions, or asking a smaller group of people more in-depth questions, uncovers dependable insights into why they buy what they buy, and whether or not they will buy something in the future, perhaps after having seen some advertising. Focus groups have been part of this method of gaining insights for years and years.
The problem with focus groups is when you look into the science, they create artificial data as a response to artificial situations and social dynamics. They take place in artificial situations and force participants to explain what they can’t explain. But nobody in a group would say ‘I don’t know how I shop’. So they guess.
Unless you are designing something for use in a focus group, focus groups are absolutely ineffective as an ethnographic research tool.
In essence, a focus group pulls together a group of complete strangers and askes them questions they can’t answer about situations past or future.