Mostly, the various mechanisms of variation in human language pose coverage challenges for information retrieval systems: texts in a collection may treat a topic of interest but use terms or expressions which do not match the expression of information need given by the user.
The benefits of CLIR technology for users with poor to moderate competence in the target language has been found to be greater than for those who are fluent.
[4] Specific technologies in place for CLIR services include morphological analysis to handle inflection, decompounding or compound splitting to handle compound terms, and translations mechanisms to translate a query from one language to another.
[5] Workshops have been held yearly since 2000 at the meetings of the Cross Language Evaluation Forum (CLEF).
[6] Early CLIR experiments were conducted at TREC-6, held at the National Institute of Standards and Technology (NIST) on November 19–21, 1997.