Modern user interface paradigms depend on direct manipulation, rapid response and immediate semantic feedback. Up until the early 80s response time was a recognized problem. But, with the advent of personal computing and graphical interfaces, user interface designers have often assumed that machines will be fast enough. Response delays were no longer an interesting problem, ever faster computers would make the problem go away. Even if we imagine that network capacity could overtake growth in usage, we are ultimately faced with the fundamental limitations of the speed of light.
Delays are here to stay.
Of course as with all such divisions the rationale was as much governed by the timetable as the content, but in general the day did move from problem statement, through theories to partial solutions. Such critical parameters can not capture the full subtlety of design trade-offs but they do allow the design space to be represented more succinctly and hence more tractably. William gave examples of the use of critical parameters in applications, including airline reservation, medical record-keeping and calendar maintenance. He discussed the potential effect of porting applications to the Web in terms of critical parameters. He did not attempt to define the full set of critical parameters for the web, thus leaving a challenge to the workshop participants.