NEXI, now and next

NEXI was introduced in INEX 2004 as a query language for specifying structured and unstructured queries on XML documents. A language expressive enough for INEX yet simple enough for users to get right. These goals have been achieved. In particular, the error rate in CAS queries has dropped from 63% in 2003 to 12% in 2004. This drop is shown to be a consequence of not only the language, but the tools introduced with it: the source code for a parser was downloaded by 13 IP addresses, while a web implementation was accessed 635 times from 71 addresses. Although NEXI is suitable for the ad hoc track, it is not sufficiently expressive enough for the heterogeneous track, or for question answering. The syntax necessary to extend to these purposes is proposed. This includes weighted terms and weighted paths. The new syntax is strictly an extension so does not invalidate any existing queries.