1. A computer-implemented method for processing multilingual documents in a document database database using a computer-implemented system comprising a processor and a display operatively coupled to the processor, the method comprising: operating the processor to perform the following generating an initial ranking of retrieved multi-lingual documents using an information retrieval system and based upon a user search query provided by a user; displaying for the user the initial ranking of the retrieved multi-lingual documents; permitting user selection of a plurality of vocabulary words based upon occurrences thereof in at least some of the retrieved multi-lingual documents; generating respective relevancies of the user-selected vocabulary words in the retrieved multi-lingual documents; generating a re-ranking of the retrieved multi-lingual documents based on the generated respective relevancies of the vocabulary words; and operating the display to display for the user the re-ranking of the multi-lingual documents, and for each multi-lingual document being displayed, also to display its initial ranking.