On user interface reference models

The proliferation of personal workstations and computer networks has enabled users to develop or otherwise access an ever wider range of applications. Unfortunately, the human-computer interface has not kept pace with the available hardware, nor with the aspirations of many users. Major advances are required with respect to the "style" of human-computer interaction -- advances in graphical techniques as well as other communications media. Moreover, this "style" should be as consistent as possible across applications. Much work remains to be done in achieving this consistency in the face of the wide variety of applications currently available. At the implementation level, much work remains to be done to accommodate heterogeneous hardware and software bases. For example, to what extent can we ensure that applications can run as well distributed over low-speed lines as over high-speed local area networks? How might we implement the human-computer interface in such a way as to be easily ported to a variety of operating systems, not just to a variety of machines running the same operating system?