Agents

The notion of agents has become a powerful metaphor for designating autonomous intelligent processes that aid the user in managing the complexity of a variety of tasks, including information retrieval, activity scheduling and process monitoring.

Our project aims at providing insight in and solutions for

In effect, agents have been characterized as the dominant human-computer interface of the future Negro. The aspects of our research as indicated above address the problems involved in defining and realizing the potential of the agent metaphor as a human-computer interface in the distributed information system domain, in particular the Web.

Modeling agent behavior

The ability to model the behavior of solipsistic and cooperative agents is a prerequisite for (a) managing the complexity of defining agent behavior, and (b) for adapting the behavior of agents to user preferences or circumstantial conditions.

Realizing agents

We choose for aiming our project at realizing agents in a Web-aware context (a) because the Web provides a rich reservoir of information, and (b) the Web offers a suitable infrastructure for defining an actual graphical user interface for employing agents. In particular, agents may be integrated with standard means for accessing the Web by means of applets. Further we wish to supply a language that allows us to program the behavior of agents in a straightforward way, adequate with respect to the models described at a more abstract level.

Architectural support

The architectural requirements for realizing agents in a Web-aware context consists of (a) high-level support for distribution to allow for notification and the communication between agents, (b) access to the Web both in terms of server-side and client-side computation, and (c) support for information retrieval and data management.

Discussion

Currently agents are in the focus of interest of numerous research groups Internet,Softbots,Software,Architecture,Survey. However, one may observe a divergence between purely formal approaches and purely pragmatical approaches, that provide an operational realization of agents lacking a solid foundation.

Although many of the ideas and concepts underlying agents have been a topic of research for decades, notably issues concerning distributed systems and programming language design, the notion of agents itself hase become a major research topic only recently. A survey of agent theories, architectures and languages is given in  [Survey]. As concerns agent theories, the main focus of attention lies on a logical analysis of intentional notions underlying the behavior of single agents, whereas for agent architectures issues of communication and cooperation between agents have been addressed in more detail. In  [Survey], concurrent logic programming languages are considered to be the ancestors of agent languages. Of immediate relevance for our own work is the Oasis programming language described in  [Oasis], which bears a close resemblance to the distributed logic programming language DLP  [DLP].

Recently, commercial agent systems have been developed for the Web. For example, General Magic has launched its Telescript Agent System, a system that employs mobile agents defined in General Magic's Telescript language. Also in  [Internet], a number of agent-like programs are described. We are reluctant to qualify these systems as 'agents', however, since they are defined in a purely operational way. We find, for complex agents anyway, a more explicit representation of the intentional aspects desirable.

In a recent issue of the CACM( 37(7), July 1994), some current trends and applications of agent research are presented. From our perspective we consider as important representatives of ongoing research:  [Software], that describes the agent communication language KQML (Knowledge Query and Manipulation Language);  [Architecture], which describes the complexity of of integrating collections of agents; and  [Softbots], which describes a number of simple agents for facilitating access to the Web.