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Irony of Internet search is that - there never is a
paucity of information - but an overdose of it. With databases that
can keep the entire Web at its fingertips - search engines almost
always can retrieve relevant pages but the challenge lies in separating
wheat from the chaff - keeping out unwanted stuff. Most engines
find more sites from a typical search query than you could ever
wade through and so finding the relevant pages from its search result
looks more like proverbial needle in the haystack situation.
We have discussed Boolean search in last issue. Its
a great tool in terms of simplicity and speed - but incapable of
differentiating search expressions which have same keywords but
in different order (hence different meaning). So, Search expressions
'Dog Bites Man' and 'Man bites Dog' retrieves virtually same result
(unless using exact phrase).
Search Engines are aware of this problem and have tried
to solve it in different ways. Directory type search engines display
search result in alphabetic order. But they are extremely selective
- so the search result seldom goes beyond one or two pages.
Spider based search engines have no such luck - so
they employ what is called 'relevance score' to sort search results.
Relevance score is a measure to bring the most relevant
pages at top of any search result. Many search engines display relevant
score of each retrieved page.
Relevance scores reflect the number of times a search
term appears, where it appears (e.g. in the title, in the meta tags,
towards the beginning of the document etc.), if all the search terms
are near each other and many other relevance parameters. Each parameter
has a different weightage. The pages are sorted by final relevance
score.
Since each search engine has its own system of calculating
relevance score - you find different search result from different
search engines even when the search expression is same.
Related Links:
Source: FAIDA
- Newsletter on Business Opportunties from India and Abroad
Vol: 3, Issue 13
July 18' 2002
Author :
Dr. Amit K. Chatterjee
(Amit worked in blue-chip Indian and MNCs for 15 years in various
capacities like Research and Information Analysis, Market Development,
MIS, R&D Information Systems etc. before starting his e-commerce
venture in 1997. The views expressed in this columns are of
his own. He may be reached at amit@infobanc.com
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