Tools for building advanced user interfaces

System developers are noticing that their design decisions strongly affect computer usability. The design of the user interface has an important bearing on the knowledge users must have to accomplish work through the user-computer interface. Recognition of this fact is leading to the development of User Interface Management Systems (UIMSs). A UIMS is a design concept for separating the details of user interaction from the details of advanced applications. This paper shows how UIMS research and research into the representation of user process knowledge (i.e., user how-to-do-it skills) can help developers understand issues involving ease of learning and ease of use. This parallel progress in UIMS development and in user modeling makes it easier to build high-quality advanced user interfaces.