1. A method for use in operating a machine-based tool for converting data from a first form to a second form, comprising the steps of: establishing, based on external knowledge of a subject matter area independent of analysis of a particular data set to be converted, a number of schema, each including one or more conversion rules for use in converting data within a corresponding context of said subject matter area, wherein said establishing comprises identifying a public schema, including conversion rules generally applied to said subject matter area independent of any entity or group of entities associated with said set of data, that establishes a structure for understanding at least a portion of the subject matter area, and wherein said public schema involves an accepted public definition of a semantic object; identifying a set of data to be converted from said first form to said second form; determining a particular context of said set of data; based on said context, accessing an associated first schema of said number of schema; and converting said set of data from said first form to said second form using an included conversion rule of said first schema.