A comparative evaluation of three implementations of a large databank, the NIOSH Registry of Toxic Effects of Chem ical Substances, has been carried out. The three implementa tions are: a printed index, a text searching computer system, and a computerised chemical databank system, with substruc ture searching facilities. Seven test queries were used, with the aim of drawing conclusions of general relevance to chemical databank searching. The computer systems were shown to have advantages over printed indexes for several of the queries, including those involving an element of browsing. Substructure search facilities were especially advantageous. Aspects of indexing of data present, and the criteria for inclusion of types of data, were also highlighted.
Tree Search Techniques for Minimizing Detectability and Maximizing Visibility