  Locating and distilling the valuable relevant information continued to be the
major challenges of Information Retrieval (IR) Systems owing to the explosive
growth of online web information. These challenges can be considered the XML
Information Retrieval challenges as XML has become a de facto standard over the
Web. The research on XML IR starts with the classical IR strategies customized
to XML IR. Later novel IR strategies specific to XML IR are evolved. Meanwhile
literatures reveal development of the rapid and intelligent IR systems. Despite
their success in their specified constrained domains, they have additional
limitations in the complex information space. The effectiveness of IR systems
is thus unsolved in satisfying the most. This article attemptsan overview of
earlier efforts and the gaps in XML IR.
