Parameter类有两个Properties: parameterType ( minCardinality 1 ) parameterValue (在过去的版本中用于制定constant value) I brought this up a while ago on this list, and no-one objected to deprecating this property, since we have valueData to do the job. parameterValue is a leftover from earlier incarnations of OWL-S. /Daniel Maybe the definition of the parameterValue needs to be changed as the "default value" that will be used in case no other value is provided. In any case, a clarification about its use needs to be documented. Evren