In automatic speech recognition programs, attempts have been made to use partial information about the phonetic structure of signals to search large lexical databases. Little attention has been given to the interaction of stress patterns and syllabic nuclei in restricting the searches. A survey of the MRC Psycholinguistic Database of British English (RP) with 38-K tokens revealed that six stress patterns (out of 17 attested) account for 96% of the tokens in the subset of two- and three-syllable words. Further, three syllabic nuclei (out of 23 attested) account for 50% of the tokens, independently of stress pattern. The interactions of stress pattern and nuclei show not only increased discriminatory power (in information theoretic terms) over either attribute alone, but also reveal significant gaps between expected and observed cases. The gaps, both accidental or principaled, further reduce the relevant search spaces and increase the usefulness of this type of partial information over other candidates. [Work supported by Alvey Grant MMI 069.]