These take the shape of face-to-face interviews. Respondents are intercepted close to where they come into contact with the service, product or experience — streets, shopping malls, parking bays, etc., depending on the nature of the research.
For instance, to understand why people buy certain products and not others, we station our interviewers close to the product display. Once a customer has bought the product, we request them to take an interview about their experiences with the said product.