Since UMDL cannot know at design-time what services will be available
in the future or what the best negotiation mechanisms are for any
given situation, its languages and protocols have been designed for
flexibility and extensibility. In the case of negotiation mechanisms,
UMDL uses a generalized auction specification to allow goods and
services to be offered under a wide variety of terms .
While generalized auctions are not the only possible kinds of
negotiation mechanisms, they offer many advantages. They provide a
structured, yet flexible market infrastructure promoting automated
negotiation due to the following characteristics:
- Mediated (vs. Unmediated):
Buyers do not have to separately find and contact every seller; a
useful property in a large-scale and dynamic environment.
Information about current status can be easily and uniformly
- Price (vs. Barter):
Under certain circumstances, price minimizes communication between
- Formal (vs. Informal):
Standardized offers simplify communication between agents.
Auction specifications consist of parameters which can be tuned to
reflect the type of good being sold, timing requirements or mechanism
properties desired. For example, a query planning service might be
sold differently depending on how it is bundled (e.g., per-query,
subscription), characteristics (topic, audience, timeliness), terms
(redistribute, read-only) or to whom it is sold (individual, library,
group). Different kinds of auctions will have advantages and
disadvantages for different types of information goods and services.
Although evaluating tradeoffs between desirable properties of
different auction types is important, the role of UMDL is not to
require that a particular auction be used in a given circumstance, but
rather to provide an open framework whereby the use of these market
facilitator agents is supported. To automate the creation and
management of auctions as much as possible, we use a system agent
called the Auction Manager Agent.
Jose M. Vidal
Tue Sep 30 14:35:40 EDT 1997