WASP -- Web Agent Support Program

8. Content

In this section we describe the underlying scientific problem our project is concerned with, and we will further detail the method(s) we will employ, and the expected results. In addition we will explain the relevance of our contribution for the scientific community and we will assess our project with respect to its scientific merits.

a. Scientific Problem

The notion of agents has become a powerful metaphor for designating quasi-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 chose 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. In particular we wish to provide 'standard' components for creating agent-based systems (including support for graphical user interfaces, access to the Web and cooperation).

Architectural support

The architectural requirements for realizing agents in a Web-aware context consists of (a) a high-level distributed language or system for programming the behavior of agents, and (b) access to the Web both in terms of server-side and client-side computation. The cooperation between agents and other components of an application requires advanced means for distributed object creation and interaction.

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 seem to be more important. 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.

b. Method

For each of the levels or facets indicated, that is modeling, realization and architecture, we will briefly describe the way we plan to tackle the problems involved.

Modeling the behavior of cooperative agents

Our approach will be based on the work already done in the context of DESIRE  [Desire]. In effect, DESIRE provides a logic-based formalism in which the cooperation between multiple components can be expressed in a declarative, compositional way. In particular, DESIRE has been employed for describing cooperative multi-agent systems for monitoring processes  [Modeling,ModelAge,Cooperation]. Research in this area will be focussed on defining cooperation in information-retrieval tasks and on expressing user-preferences and information-needs in an adequate way. Other topics of interest include modeling users as agents and the verification of agent specifications.

Realizing Web-aware agents

The development of Web-aware applications has been addressed in the DejaVu project  [Applications,Music]. The approach taken there was to employ object-oriented design technology for realizing a component-based approach to integrating multimedia in Web-based hypermedia applications. The development of generic components for realizing agent-based systems will be addressed in the same fashion, in order to allow for the integration of adequate multimedia and graphical user interface support.

Architectural support

In the DejaVu project we have already gained expertise in the area of language embedding and integration  [DLP,Hush,VE95]. It is our intention to employ the distributed logic programming language DLP  [DLP] as a high-level vehicle for programming the behavior of agents. We strive on the one hand for a close integration of the DESIRE framework and DLP and on the other hand to extend DLP with the primitives needed to access the Web and to create adequate graphical and multimedia user interfaces. Also, we have gained some expertise in supporting cooperative work  [Chatting]. This work needs to be extended to allow for agents to join a session in which they may communicate and cooperate. In addition, to allow for managing the information retrieval and management tasks involved in dealing with the Web, helper applications must be developed which employ the native HTTP protocol of the Web. An information retrieval tool  [Bra,Fish,Search] has been developed at the TUE and integrated into a WWW browser. This tool is also available as a server-side tool. The latest version uses multiple search-agents operating in parallel. Current Web developments make it possible to integrate agents into browsers in a more flexible way, by using applets or plug-ins. A method for improving the use of the internal structure of documents has been defined by means of object-oriented databases. An intelligent retrieval helper application needs to be aware of the internal structure of documents, and needs to be able to store the information it finds in a similar structure. A Web-server based on an object-oriented database  [OODB] has been developed for this purpose.

Discussion

Needless to say that we wish to maintain a close integration between the efforts involved in the research concerning the aspects mentioned. In particular, we intend to develop a prototype agent application Pamela (Personal Assistent for Managing Electronic Archives) as a point of reference.

c. Results

The WASP project is aimed to result in a framework (in its extended meaning) for the development of agent-based Web-aware applications. Such a framework includes: In addition we wish our work to result in a generic agent application Pamela that demonstrates the capabilities of our approach. The intended results, divided over the various aspects of our project, are summarized below.

Modeling the behavior of cooperative agents

Realizing Web-aware agents

Architectural support

d. Contribution

Scientifically, our work is of significance for the areas of In particular, because we propose to take an integrated approach to the problem of providing agent support for Web-aware applications, the efforts coming from the different areas of expertise of the participants results, hopefully, in a more encompassing theoretical and practical framework than would have been possible for each of the participants individually, or more in general in a more mono-disciplinary approach.

3. Merits

Clearly our project covers both fundamental and pragmatic aspects. It is application-oriented in the sense that it is aimed at satisfying the conditions for developing actual agent-based applications. However, it is fundamental to the extent that it is based on well-founded principles of modeling and software engineering. In the area of information retrieval, moreover, we hope to come up with a substantially new approach for the discovery of new (recent) interesting and relevant information in a large distributed hypermedia information system such as the Web.

mailto:eliens@cs.vu.nl ( Thu Sep 26 14:04:33 MET DST 1996 )