The Hatter's watch nicely illustrates the effect of idiosynracy in system design. Really, a watch could provide any number of features, but most watches designed for people put a high priority on telling the correct time of day. Thus, the Hatter's watch is an excellent example of bad human engineering. By human engineering we mean "the selection among design alternatives so as to relate to people." Carroll's stopped watch is the ultimate in poor human engineering because the user must do all the work.

This paper presents the formalism of Production Systems and investigates its applcation to defe the Syntax and trlation of programming languages. Several properties appear well-suited to this task: 1) the formalism can be used to specify exactly the syntax of a computer language, including context-sensitive requirements; 2) the specification of the context-sensitive requirements on syntax can be isolated from the context-free requirements; 3) the same formalism can be used to specify more general structural properties, including the translation of one language into another. The notation has been developed with readabifity as a prime designissue. The following examples are given:1) aspecificationofthesyntaxofasmallbutdifflcultsubset of PL/I;2) a specification of the rules for translating lambda-culus expressions into, normal form.