Search for information is no longer exclusively limited within the native
language of the user, but is more and more extended to other languages.
This gives rise to the problem of cross-language information retrieval (CLIR),
whose goal is to find relevant information written in a different language to a
query. In addition to the problems of monolingual information retrieval (IR),
translation is the key problem in CLIR: one should translate either the query
or the documents from a language to another. However, this translation
problem is not identical to full-text machine translation (MT): the goal is not
to produce a human-readable translation, but a translation suitable for finding
relevant documents. Specific translation methods are thus required.
The goal of this book is to provide a comprehensive description of the
specific problems arising in CLIR, the solutions proposed in this area, as
well as the remaining problems. The book starts with a general description of
the monolingual IR and CLIR problems. Different classes of approaches to
translation are then presented: approaches using an MT system, dictionary-
based translation and approaches based on parallel and comparable corpora.
In addition, the typical retrieval effectiveness using different approaches is
compared. It will be shown that translation approaches specifically designed
for CLIR can rival and outperform high-quality MT systems. Finally, the book
offers a look into the future that draws a strong parallel between query
expansion in monolingual IR and query translation in CLIR, suggesting that
many approaches developed in monolingual IR can be adapted to CLIR.
The book can be used as an introduction to CLIR. Advanced readers can
also find more technical details and discussions about the remaining
research challenges in the future. It is suitable to new researchers who
intend to carry out research on CLIR.
Table of Contents:
Using Manually Constructed Translation Systems and Resources for CLIR
Translation Based on Parallel and Comparable Corpora
Other Methods to Improve CLIR
A Look into the Future: Toward a Unified View of Monolingual IR and CLIR?