For documents to be indexed and searched for in a database, a computer-implemented method, and information retrieval system

摘要

An information retrieval system stores and retrieves documents using particles and a particle-based language model. A set of particles for a collection of documents in a particular language is constructed from training documents such that a perplexity of the particle-based language model is substantially lower than the perplexity of a word-based language model constructed from the same training documents. The documents can then be converted to document particle graphs from which particle-based keys are extracted to form an index to the documents. Users can then retrieve relevant documents using queries also in the form of particle graphs.