A library serves a community of users by making available information
content and services that are valued by that community. A
traditional, physical library is thus not simply a building that
houses information, but rather a complex configuration of information
goods and services that have been carefully selected and organized
around the needs of a user community.
In a digital library, the content and services are electronically
available, and user communities are no longer geographically defined.
Realizing a digital library therefore includes difficulties in
digitizing contents, computerizing services, and networking together
users. But even if these difficulties are overcome, the result can
well be an overwhelming tangle of possible information sources without
the structure and selectivity that renders a library navigable. In
other words, if the administration of a traditional library is
challenging, the administration of a digital library can border on
impossible due to the magnitude of content and services available, the
rate of change in what is available, the size of a user population
that is not bounded by physical proximity, and the evolving nature of
that population.
One answer to this challenge is to rely on traditional methods of
putting administrators at the center of the endeavor, to attract,
register, and track a user community, to seek and include the content
that will benefit the community, and to provide the most valuable
services for tasks such as organizing, searching, abstracting, and
disseminating the content. An alternative approach, however, is to
move as much of the administration into the digital infrastructure as
possible. The goal is to provide mechanisms by which a digital
library can continually reconfigure itself as users, contents, and
services come and go. These mechanisms should encourage:
Flexibility: They should be able to embody a wide variety of
policies to realize different flavors of libraries (public, corporate,
university, personal,...) Extensibility: Providers and
consumers of information goods and services should have incentives to
join the library and abilities to find their counterparts.
Scalability: As the plethora of users, goods, and services
grows, the underlying, computerized administration of the library
should not bog down.
Toward this end, the University of Michigan Digital Library
(UMDL) is structured as
a collection of agents that can buy and sell services from each other
using our commerce and communications infrastructure. While one of
the emphases of the UMDL is to provide a working testbed to improve
secondary education [9], a second emphasis is on the
definition and design of the infrastructure, and the kinds of agents
that exist in it, that allow decentralized (scalable) ongoing
configuration of an extensible set of users and services. We refer to
the services/protocols offered by this infrastructure as the Service
Market Society (SMS).
The SMS requires the integration of numerous agent technologies for
knowledge exchange, commerce, learning, and modeling. In this paper,
we describe how we have brought these technologies together to create
a prototype SMS in which a changing population of agents can find each
other, enlist each other's aid (for a price), decide on the terms of
an interaction, and learn to differentiate among providers. We use
our prototype to demonstrate how these technologies contribute to
providing a flexible, extensible, and scalable digital library.
Before this, however, we start with an overview of SMS in
Section 2, and the component technologies of the
UMDL ontology (Section 3) and auctions
(Section 4). These technologies allow flexibility in
the UMDL configuration policies, extensibility in what can be
bought/sold in the SMS, and scalability by using demand (as
represented by price) as incentive for replicating services
(Section 5). Robust performance in such a
society, however, also requires that participating agents make
informed buy/sell offers for the goods and services, and that they
have the ability to recognize and learn from whether another party
keeps its end of the bargain (Section 6).
Jose M. Vidal
jmvidal@umich.edu
Tue Sep 30 14:35:40 EDT 1997