1. A method of merging results in distributed information retrieval, comprising: submitting a query to a plurality of components, wherein a component is a search engine working on a document collection; receiving results from each component in the form of a list of documents; estimating the success of a component in handling the query to generate a merit score for a component per query; applying the merit score to the results for the component; and merging results from the plurality of components by ranking in order of the applied merit score.