COMPUTER-STORAGE AND RETRIEVAL OF GENERIC CHEMICAL STRUCTURES IN PATENTS .17. EVALUATION OF THE REFINED SEARCH

Results are presented for the atom-level search, called the refined search, for matching components of generic chemical structures. The refined search is the last and most discriminating search strategy used by the Sheffield generic structures system and is performed after the faster screening stages, bit screening, and reduced graph screening. It operates on the real atom representations of components of the generic structure which are defined by reduced graph nodes, nodes which represent aggregates of atoms of the original chemical graph which are structurally similar. The nature of generic structures means that parts of a structure may be expressed in terms of real atoms and bonds and parts in terms of homologous series identifiers such as alkyl. The fundamental problem concerning the refined search is determining equivalences between these two types of representation. Search results are presented for four query database searches against one file database. The methodology and results of the screening searches are also briefly described.