He is best known for popularizing the concept of wicked problem,[1] but his influence on design theory and practice was much wider.
Rittel and Melvin Webber published the seminal paper on Wicked Problems in the journal Policy Sciences in 1973.
It has served as a regular teaching tool, in order to demonstrate the typical difficulties of design and the different ways of dealing with them.
The recent availability of "hypertext" data-structures and user interfaces—even on small microcomputers and moderately priced workstations—has allowed the design of IBISes which are much more "user-friendly" than their predecessors.
Some crucial old weaknesses of IBIS remain the same: the danger of getting lost in the web of cross-references, the lack of a "synoptic" overview of the state of resolution, and the "logic of the next question", i.e. the problem of prestructuring the possibilities for guiding the designers' deliberations into plausible directions.