Breadth and Depth of Semantic Lexicons

Whereas the former has been regarded as a topical issue for quite some time, the latter is only now receiving its due attention. This workshop will concentrate on lexical rules as a regulator of breadth and depth of the lexicons. Lexical rules are known under a variety of names, e. g., Leech's (1981) "semantic transfer rules," "lexical implication rules" of Ostler and Atkins (1991) and others. They are also addressed in the framework of such theories as the generative lexicon of Pustejovsky (1995). Such linguistic frameworks as LFG and HPSG have also used the concept, albeit in a different sense and for a different purpose. At the same time, theoretical accounts of the use of lexical rules (such as, for instance, preemption or blocking) are rather too general and underspec-ified to support actual processing. The workshop will stress issues connected with the practical application of lexical rules: when to apply the rules, how the rules influence system design, how to reexamine and adjust the theoretically posited rules in view of practical needs and evidence. Another central issue for the workshop will be large-scale acquisition of computational-semantic lexicons for practical applications. We are mainly interested in examining the following trade-offs: the coverage vs. the depth of existing semantic lexicons vs. the effort involved in building them.