one of the simplest ways to explore whether or not users are happy with a product, service or system is to ask them. interviews basically comprise a series of question, which are posed directly to the participants. when interviewing users for example, product designers can ask how they feel when using the product, whether it is easy or difficult to operate, whether they enjoy using it or find it frustrating or annoying. there are three broad categories of interviews that a designer can draw upon-unstructured,semi-structured and strucured