I this talk I will discuss the various challenges associated with
the automatic invocation of a Web Service by an autonomous agent.
I
will show how a simplified protocol language can be used to describe
the pattern of interaction with a single Web Service, and how these
protocols can complement existing semantic markup techniques, e.g.
OWL-S. This talk will be a rehearsal for my presentation at
the AAAI
Fall Symposium on "Agents and the Semantic Web".