The document provides a history and overview of how search engines work. It discusses the evolution of major search engines from the 1990s to present day. It then describes the key components of search engine architecture, including crawling websites, indexing content, ranking algorithms, and providing search results. Specific algorithms like PageRank and updates from Google are explained. The document also covers how search engines determine relevancy, fight spam, and present results on the search engine results page.

1. How Search Engine Works ?
Presented by Mohammed Azharuddin
Digital Marketing Trainer

2. History of Search
• 1990 – Archi Query Form
– FTP based file search engine
• Feb 1993 – Excite.com
– General word relation based search
• Oct 1993 – AliWeb
– Manual submission engine
• Jan 1994 – Altavista
– First natural language search engine

3. • Jan 1996 – Backrup
– Started by Larry Page and Segrey Brin
• Sep 15 1997 – Google.com
– First search engine with Page Rank Technology
• 1997 – Yandex.com
– Russian based search engine
• 1998 – MSN Search
– Microsoft Rival to Google

4. • 2000 – Baidu.com
– Chinese based search engine
• 2008 – duckduckgo.com
– Non tracking search engine
• 2009 – Bing.com
– Microsoft Rival to Google
• 2010 – Blekko.com
– Spam and Virus free search
http://www.searchenginehistory.com/
http://www.google.co.in/about/company/history/
http://www.wordstream.com/articles/internet-search-engines-history

5. The Google Story

6. Search Engine Architecture
• Every search engine is based on following
– Crawling
– Indexing
– Algorithms
– Results
– Fight Spam

7. Google Architecture
http://infolab.stanford.edu/~backrub/google.html

8. Search Engine Architecture
Crawler
Store
Indexer
100 Million GB
indexes
indexes
Search
Interface
Algorithms
(Programs)
trash
trash
trash
Sorted based on Content / Factors
WWW
60 Trillion Pages
Or
60 Lakh CroreLive Google Example

9. Algorithms
• Programs and Formulas to get relevant results
– Page Rank
– Spelling Check
– Synonym check
– Auto complete
– Query Understanding
– Safe Search
– User Context

10. Page Rank Algorithm
• Google's first algorithms, which looks at links
between pages to determine their relevance.
• PR is a number generated for each page
available in Google Index
• PR Toolbar Range
– NA to 10 (Best Rank) : This is based on Log Scale
of 0 – 10
• Real Page rank is calculated based on number
of pages in index, which can be 0.15 to
Trillions

11. Toolbar Vs. Real PR
Toolbar Real PR
0 0 - 10
1 100 - 1,000
2 1,000 – 10,000
3 10,000 – 100000
4 100000 – 1000000
5 1000000 - 10000000
http://www.webworkshop.net/pagerank_calculator.php3

12. PR Formula
Updated Formula
Old Formula
D = Damping Factor ; PR(N) = PR of Linking Site ; L(N) : No of Outbound Links

13. Example
http://en.wikipedia.org/wiki/PageRank
http://www.cs.princeton.edu/~chazelle/courses/BIB/pagerank.htm

14. Fighting Spam
• Spam refers to websites which uses un ethical
practices for Search Rankings
• To fight the spam Google release updates
frequently called as “Algorithm Updates”
• Google changes its search algorithm around
500 – 600 times every year.
• Some of them are major and few are minor
updates

15. Major Updates

17. • Panda Update - February 23, 2011
– This algorithm target the sites with thin content,
content farms, duplicate content, sites with high
ad-to-content ratios, and a number of other
quality issues.
– Affected 12% queries on launch
– Recent update : Panda 4 – May 19 2013

19. • Penguin Update – April 24, 2012
– This algorithm target the sites which over optimize
the websites, uses excessive links.
– Affected 3% queries on launch
– Recent update : Pengiun 2.1 – Oct 4 2013

21. Humming Bird Update – August 2013
• This algorithm understands the context of the
query by analyzing the words in query
• It can automatically rewrite the query internally
based on certain words like “Near”, Vs, How to,
Where, Who is …. Etc
• Many queries are provided as “ONE BOX
ANSWERS” to give the quick answers.

22. How it Works ?
User Query
Query
Translator
Modified
Query
Index

23. One Box Answers Queries
• When is Independence of India
• Time in India or Time in Toronto
• 1$ to INR
• 1Mile to Kms
• Banana Vs. Apple
• Who is wife of Bill Gates
• What is my IP
• who invented www
• Show me pictures of taj mahal

24. Search Engine Results Page
(SERP)

26. Types of Results
Paid Results
PPC Ads
Comparison Ads
Shopping Ads
Non Paid Results
Organic Web
News Results
Image Results
Local Results
Video Results
Site Links
Schema Data

27. Click Through Rate (CTR)
• CTR is a measure to understand how many users are
clicking on the site from SERP
• CTR helps to understand the user response
• The top four positions “above the fold” for many
desktop users, receive 83% of first page organic
clicks.
CTR = (No of Clicks/No of Impressions)x100

28. 2011

29. 2012 CTR Results

30. Branded Vs. Un Branded

31. Thank you
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