all about working of google search engine

1. RUCHIR KUMAR GUPTA
BTECH FINAL YEAR(I.T.)
0701013084

2. CONTENTS
INTRODUCTION
HISTORY
WORKING
TYPES OF SERCH ENGINE
ADVANTAGES
CONCLUSION

3. INTRODUCTION
Search engine is a software program that
searches for sites based on the words that you
designate as search terms.
Search engines look through their own
databases of information in order to find what
it is that you are looking for.
“Search engine” is the popular term for an
Information Retrieval (IR) system.

4. HISTORY
Archie – First search tool for the Internet
Gopher – indexed plain text documents
Jughead – searched the files stored in Gopher
index system.
Wandex – first Web search engine

5. How do Search Engine Works
 Spiders
 Robots

6. FORMULA
Larry Page and Sergin Brin at Stanford University gave it.
 PA=(1-d)+d (PR(T1))/C (T1)+…+PR (Tn)/C (Tn)
Where
 PR(A): Page Rank of page A
 PR(Ti): Page Rank of pages Ti which link to page A.
 C(Ti): the no of outbound link on page Ti d: damping
factor in the range of 0<d<1,usually set to 0.85.
The highest the PR, the better the inbound link, so it would
seem.

11. APPROXIMATING
RELEVANCE
 Statistical similarity is used to estimate the relevance of
an query to answer.
 Consider the query MAHENDRA SINGH DHONI
1) A good answer contains all three words,and more
frequently the better,we called this term frequency (TF).
2) Some query terms are are more important-have the
discriminatory power-better than others.

12. Resolving a Query
Consider ( cat hat mat )
Select a word from query ( “cat” )
Retrieve the list for the word cat
Find the best ranked document and look up the
mapping table.
Retrieve and Summarize the docs.

13. Search Engine Modules :
A document processor
A query processor
A search and matching function
A ranking capability
 Summarizing and Presenting documents.

14. TYPES OF SEARCH ENGINE
Crawler-Based Search Engines
Human-Powered Directories
Hybrid Search Engines" Or Mixed Results

15. Google use spiders
Large index of keywords.
Google’s PAGE RANK .
1.frequency and location of keywords
within the Web page
2. Web page history.
3. number of other Web pages that link
to the page in question

16. ADVANTAGES
 It organizes the world ‘s information.
 It makes the information universally accessible.
 It makes the information useful.
 Helps people to interact one another.
 Helps to know about the products and goods.
 Helps the people to know about the society.
 Any information can be gathered from google.

17. CONCLUSION
Search engine plays important role in
accessing the content over the internet, it
fetches the pages requested by the user.
 It made the internet and accessing the
information just a click away.
The need for better search engines only
increases
The search engine sites are among the most
popular websites.