1. A method for isolating application specific information in XML data, the method comprising the steps of: receiving one or more criteria that identifies nodes within a collection of XML documents to ignore; receiving a query that specifies a path operation based on a path; wherein one or more of said identified nodes is under said path; and based at least on the one or more criteria, computing the path operation as if one or more of said identified nodes is not in the collection of XML documents; wherein the method is performed by one or more computing devices.