The Semantic Linker
David G. Stallard, Robert Bobrow · 1993
This paper presents the Semantic Linker, the fallback component used by the the DELPHI natural language component of the BBN spoken language system HARC. The Semantic Linker is invoked when DELPHI's regular chart-based unification grammar parser is unable to parse an input; it attempts to come up with a semantic interpretation by combining the fragmentary sub-parses left over in the chart using a domain-independent method incorporating general search algorithm driven by empirically determined probabilities and parameter weights. It was used in the DARPA November 92 ATIS evaluation, where it reduced DELPHI's Weighted Error on the NL test by 30% (from 32% to 22%).