Abstract: Disclosed is a system architecture, components and a searching technique for an Unstructured Information Management System (UIMS). The UIMS may be provided as middleware for the effective management and interchange of unstructured information over a wide array of information sources. The architecture generally includes a search engine, data storage, analysis engines containing pipelined document annotators and various adapters. The searching technique makes use of a two-level searching technique. The data processing system includes a token inverted file system storing tokens obtained by at least one tokenizer from document data. An annotation inverted file system stores annotations, a list of one or more occurrences of each annotation, and, for each listed occurrence, a set comprised of at least two token locations spanned by the respective annotation.