Semantic web services hold the promise of greatly increasing interoperability among software agents and web services by enabling content-based (as opposed to format-based) automated service discovery and interaction. However, as different services may well use different, only partly compatible ontologies to describe their capabilities, some amount of ontology mapping or translation will be required during the various stages of service discovery and utilization. In this paper, we reexamine some of the processing assumptions that were made in the development of semantic web service models like DAML-S in order to uncover the very different roles of semantic translation in the subprocesses of service discovery, service process model interpretation, task negotiation, service invocation and response interpretation. We present examples and arguments showing how several different styles of translation will be required based on the informational context and perspectives of agents in each of these stages.