Combining Information from Multiple Internet Sources

3.4 Common algorithms
This part of chapter 3 presents algorithms that are commonly used throughout the
application. This chapter presents the purposes of the algorithms and their pseudo codes. Also a
short description of each algorithm is provided.
3.4.1 Ranking algorithm
Listing 3.4.1 presents the pseudo code of the algorithm for the initial URL ranking. This
initial ranking is being performed before the Game theory and Auction methods (not the Consensus
method) can start their main computational parts. Its purpose is to calculate the confidence values of
the Search Agents about a certain URL. The confidence value in general is calculated as
follows: result set of agent − position of the URL in the result set . However the Game theory and
the Auction methods require that each of the result sets contain the same URLs, not necessarily at
the same places. In other case the algorithm breaks, since agent may now nothing about a certain
URL and therefore the comparison of ranks of this certain URL cannot be performed. This
algorithm also insures that this assumption is fulfilled by updating the result sets with missing
URLs. Algorithm also determines if the main computational parts of the two aforementioned
approaches can be even performed. The rule is as following: if for all pairs of result sets say
Aand
B the A ∩ B = ∅ then the main part of the Game theory and Auction can not start. If there is a
result set say that has no common URL with any other result sets it is removed from the process at
the very beginning as being not suitable for the algorithms which require every URL to be in every
result set.
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