In today's world of expanding and overwhelming choices, users' abilities to discover and choose among networked information resources becomes critical. The rate at which new resources appear on the network has passed beyond anyone's ability to track and manage by simply becoming familiar with what's available and reviewing new resources as they appear. Unless we solve the discovery and selection problems, new resources will have increasing difficulty in reaching audiences, which may inhibit both the growth of information content on the network and the diffusion of new technological advances in retrieval and access systems to the network's user community.
Current resource discovery systems for World-Wide Web index the networked information resource soley by its content. And, because they cannot provide the topic-specialized view while searching, users can retrieve unrelevant results deviated from their interest, which results in degraded browsing efficiency. Also they cannot reflect the knowledge of users which was accumulated while repeatedly using the system.
In this paper, we survey approaches for solving these problems in the resource discovery system for World-Wide Web and we propose Web Agent model which is a kind of Information Agent for NetAgent Model, responsible for World-Wide Web information space. We also implement NetAgent+, a combination of implemented Web Agent and completed NetAgent implementation which was not perfectly implemented especially for collaborative indexing part. And finally we analyze the result.