it's about of search engine...

1. SUBMITTED BY:Rishabh Agrawal
SUBIMTTED TO:AVENASH SIR

2. INDEX
• INTRODUCTION
• WORKING
• FACTS
• ADVANTAGE
• LIMITATIONS
• USES

3. Search Engines
What is a Search Engine?
• Software that enables users to search the Internet or Intranet using keywords.
• A program that acts as a catalogue for the Internet or Intranet.
• A web search tool that automatically visits websites (using crawlers), records and indexes them within its
database, and generates results based on a user's search criteria.
Popular Search Engines

4. dictionary definitions
search
COMPUTING (transitive verb) to examine a computer file, disk, database, or
network for particular information
engine
something that supplies the driving force or energy to a movement, system, or
trend
search engine
a computer program that searches for particular keywords and returns a list of
documents in which they were found, especially a commercial service that
scans documents on the Internet© Tefko Saracevic 4

5. Search Engines
How do they work?
• Web Crawling
Automated “spider” that follows links and then analyses content in pages to determine what should be
indexed. Metadata is very important in this phase.
• Indexing
Data about web pages are stored in an index database for use in later queries. Some search engines, such
as Google, store all or part of the source page (referred to as a cache) as well as information about the
web pages.
• Searching & Results
The engine looks up the index and provides a listing of best-matching web pages according to its criteria.
The usefulness of a search engine depends on the relevance of the result set it gives back.

6. Search Engines
University Search Engine Statistics
• The University uses Microsoft SharePoint Portal Server 2003
• ~88,000 web pages are crawled every day
• The crawl starts at 6:00am every day
• The crawl takes ~ 20 minutes to complete
• The search engine is currently crawling:
– www.unisa.edu.au
– www.unisanet.unisa.edu.au
– www.library.unisa.edu.au

7. elaboration…
similarities, differences
• all search engines have these basic parts in
common
• BUT the actual processes – methods how they do it
– are based on various algorithms & they differ
– most are proprietary with details kept mostly secret but
based on well known principles from information
retrieval or classification
– to some extent Google is an exception – they published
their method© Tefko Saracevic 7

8. limitations
• every search engine has limitation as to
– coverage
• meta engines just follow coverage limitations & have more of
their own
– search capabilities
– finding quality information
• some have compromised search with economics
– becoming little more than advertisers© Tefko Saracevic 8

9. use of search engines
… among others
© Tefko Saracevic 9

10. Search Engines
When I search I don’t get good results …
Four possible causes:
• No Content
There is no content that matches your search query.
• Bad search phrases
You are putting in really bad search phrases!
• Bad search engine
The search engine isn’t very good, or isn’t searching the content that it should be.
• Bad content
The content that you want exists, but the metadata and text within the page is not optimised for a search
engine.

11. how to find a search engine?
• variety of resources that list or categorize engines
• SearchEngines.com
search for engines by topic, geography, reference
Search Engine Guide
engines categorized by topic; other engine information
Search Engine Colossus
– international directory of search engines by country, topic from 198 countries and 61
territories; engines in choice of languages
Phil Bradley’s country based search engines
over 2000 serach engines from countries all over the globe© Tefko Saracevic 11

12. where to find out?
• information about search engines in sources that
have updates, news, tips for searching and more – a
MUST for searchers :
– Search Engine Watch
• ratings, news, statistics, charts, explanations, tutorials
– Search Engine Showdown
• “The users’ guide to web searching” - run by a librarian, news links, ratings
Virtual Chase
a site about “Teaching Legal Professionals How To Do Research;,” this section
has very good tips and links for consideration of quality on the web© Tefko Saracevic 12

13. THANK YOU