In our experience, one of the most effective ways of understanding a consumer’s buying behaviour, is to accompany them on a shopping trip – something we call "Accompanied Shops".
Respondents are pre-recruited and invited to spend 45 minutes to an hour walking around a store, as if they were carrying out their routine shopping. A Senior Researcher accompanies them and conducts a depth interview as they tour the store. There is usually 15 minutes or so to spare at the end where the Researcher and respondent can sit down and discuss other topics from the topic guide (contains questions to be covered during the process). Alternatively, the time can be used to visit a competitor store and make comparisons between the two.
As well as accompanied shops, we also carry out "Intercepts". These are similar to accompanied shops but respondents are recruited in situ during their shopping trip. We use recruiters to approach people in store and ask them to take part in an interview. The interview tends to be shorter (10-15 minutes) rather than the 45 minute pre-recruited accompanied shop.
The obvious advantage of these approaches is that the Researcher can see first hand, the types of products the respondent is drawn to, the type of questions they may ask staff, what they think of the in-store environment and promotions etc.