Direct manipulation user interfaces have proven their worth over two decades, but they are still in their youth. Dramatic opportunities exist to develop direct manipulation programming to create end-user programming tools, dynamic queries to perform information search in large databases, and information visualization to support network database browsing. Direct manipulation depends on visual representation of the objects and actions of interest, physical actions or pointing instead of complex syntax, and rapid incremental reversible operations whose effect on the object of interest is immediately visible. This strategy can lead to user interfaces that are comprehensible, predictable and controllable. Direct manipulation interfaces are seen as more likely candidates to influence advanced user interfaces than adaptive, autonomous, intelligent agents. User control and responsibility are highly desirable.
Note: This paper is adapted, with permission of the publisher, from: Designing the User Interface: Strategies for Effective Human-Computer Interaction (3rd Edition), Addison Wesley, Reading, MA (1997).