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Combining Information from Multiple Internet Sources

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application presented in this paper combines the retrieved results using advanced methods.<br />

In this approach application utilizes agents as experts in knowledge extracted <strong>from</strong> the<br />

results provided by search engines. It uses JADE agent framework to create a multi-agent<br />

environment which aids information retrieval. It is interfaced through a web page when one can<br />

input a query and wait for the result. In the core of the system agents serve as miners of data <strong>from</strong><br />

multiple search engines. Simply saying, they possess the knowledge that we are apparently looking<br />

for. So, when we ask several experts the same question we expect that they will provide us with the<br />

best results possible. Would not it be better if they arrived at some agreement about the answer thus<br />

giving us a single combined opinion This thesis aims at answering those questions. It investigates<br />

coherency and performance of each of the three methods used for filtering the answers so that the<br />

filtered result sets are smaller but hopefully more meaningful. Those methods are then compared<br />

with each other; to see which one provides the most promising results.<br />

There are three methods utilized in this work for yielding the final results: Game theory,<br />

Auction and Consensus. In the Game theory approach the process of combining results is compared<br />

to a game in which the game players are agents that decide about the information destination by<br />

either discarding or keeping it. An Auction based approach is almost similar to the “real-life”<br />

auction, but here agents decide about which information can be obtained for the lowest price.<br />

Consensus method uses more centralized approach since it takes the highest-ranked information<br />

<strong>from</strong> all result sets and checks how common is this result among those obtained <strong>from</strong> all search<br />

engines. All of those methods are described in the thesis; their implementation and effectiveness are<br />

presented.<br />

While consensus algorithm was already used as a tool for combining information <strong>from</strong> search<br />

engines [1], two other algorithms: Game theory and Auction were used for a different task - as<br />

methods of negotiation in Agent-based system for classification tasks - the NeurAge system,<br />

described in [7], [8] and [9]. Since Consensus based approach had been used as a way for<br />

combination of information retrieved <strong>from</strong> multiple <strong>Internet</strong> sources, there was no need for adapting<br />

the algorithm to our needs - it was used in the same manner as in [1]. Furthermore, in the AGWI<br />

system search engines were selected randomly – there were more search engines than agents<br />

utilizing those. On the other hand, Game theory and Auction required adjusting to deal with data<br />

fundamentally different <strong>from</strong> what they were dealing with in their original version. Adjustment<br />

details are presented further in the paper; mainly in chapter 3.<br />

1.1 Aim of the thesis<br />

Are the Game theory based, Auction based and Consensus based approaches a good way of<br />

combining the information obtained <strong>from</strong> multiple <strong>Internet</strong> sources By creating an application<br />

3

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