Let's ask the users [user interfaces]

Tools, techniques, and concepts to optimize user interfaces are presented. Many aspects of usability can best be studied by simply asking the users. This is especially true for issues related to user satisfaction and anxiety, which are hard to measure objectively. Questionnaires and interviews are two methods you can use to determine how people use a system and what features they particularly like or dislike. Both methods are indirect: they do not study the interface itself but rather users' opinions about it.