This work was then extended to explore the application of relevance feedback techniques to Japanese language retrieval. Results from all these experiments were very positive indicating that information retrieval techniques, in particular term weighting, can be applied successfully to different languages. Although for best performance some specialised tuning to the individual language is generally required. For example, Japanese text has no spaces between words and a technique must be used to segment it into appropriate indexing units, e.g. words or charactr n-grames. The development of online information repositories, due principally to the current expansion of the World Wide Web, is creating many opportunities and also problems in information retrieval.
Online documents are available internationally in many different languages.
This enables users to access directly hitherto unimagined sources of information. However in conventional information retrieval systems the user must enter a search query in the language of the documents in order to retrieve it. This presupposes that the user is able to write in the language of all possible relevant documents. This restriction clearly limits the amount of information to which an individual user will have access. Cross-language information retrieval enables a user to enter a query in a language in which they are fluent, and uses language translation methods to retrieve documents originally written in other languages.