Title Indexes as Alerting Services in the Chemical and Life Sciences

The principles underlying alerting services are discussed. General alerting services ( as distinct from SDI systems) need to transfer to their users a large quantity of current but mainly irrelevant information as speedily as possible. As title indexes are the easiest to prepare, and are therefore common, the user needs to know how much significant information is not discernible from a documents title. This is estimated to be 20-25% but can vary with subject and type of information sought. If a search of, say, Chemical Titles is made, ignoring synonyms but allowing for all syntactical variants, only about one third of the significant information will be recovered. Synonyms and other nomenclature problems are discussed. Delay times and time of use are the two most important factors in evaluating an alerting service and are reviewed for some typical services.