- From: Gregory Huczynski <greg@dcs.gla.ac.uk>
- Date: Fri, 5 Mar 2004 11:00:44 +0000
- To: public-sws-ig@w3.org
Hi, I'm a newcomer to the area of Web Services, and I've recently started investigating the current research into how services are discovered, and a particular one selected that suits the user's (or application's) needs. I'm interested in how these procedures can be done automatically by some agent-like software entity. I've read quite a few position-style papers (e.g. Semantic Web Services, McIlraith et al, IEEE Intelligent Systems, 2001), which advocate describing and advertising services using semantic richer descriptions written in DAML+OIL and OWL. The argument is given that these richer descriptions will be more amenable to automated manipulation and reasoning than those currently provided by discovery mechanisms such as UDDI. However, from reading these papers, I am slightly confused by a basic issue. Let's consider an example given in McIlraith et al's paper: .. "A user might say, for example, "Find a service that sells airline tickets between San Francisco and Toronto and that accepts payment by Diner's Club credit card"". I assume that with the agent-OWL-description approach, this problem would be solved by an agent reasoning over the semantic markup of the available services, identifying those that meet the user's constraints. However, in order for the agent to book a ticket automatically from a service, it must be able to communicate with it: it must know and understand the service's interface (specified, say, in WSDL). So, my question is this - for problems like the example above, before any reasoning can be done to ensure we meet user constraints, is the service search-space first narrowed down to only those services that implement a WSDL (communications) interface understood by the agent? For example, in solving the problem above: - Assume that a standard BookAirlineTicket WSDL interface has been defined. Lots of airline ticket services export this interface. - Assume that the user's agent knows and understands the BookAirlineTicket interface (it could communicate with a BookAirlineTicket service) - In solving the problem, the agent first narrows its search to those advertised services that export the BookAirlineTicket interface - The agent then reasons over the identified BookAirlineTicket services' descriptions, and identifies those that meet the user's constraints. - The agent then offers these matched services to the user, or books the ticket itself. Basically, in order for a service to be discovered, selected and used automatically, do we not require an initial search-space constraining step based on the notion of known / previously-defined service function interfaces? Apologies for writing such a long email for such a basic question! Thanks in advance Gregory Huczynski Department of Computing Science University of Glasgow
Received on Friday, 5 March 2004 07:34:25 UTC