11. The method of claim 9 , further comprising: retrieving context metadata for the at least two of the plurality of facts; determining that the at least two facts have different units of measure based on the retrieved context information.
9. The method of claim 8 , further comprising: parsing the markup language of the taxonomy document to identify a concept element having a preferred label role value indicating that facts associated with the concept are in a calculation relationship, wherein parsing the markup language of the instance document comprises parsing the markup language of the instance document to identify facts tagged with the identified concept.