Presentation on "How the Search Engine Works"

1. Assignment
Topic-How Search Engine works?Topic-How Search Engine works?
Submitted to-Submitted to- Al Imtiaz (Lecturer)Al Imtiaz (Lecturer)
((CSE & ITCSE & IT))

2. Prepared by-Prepared by-
Sheikh Mohammad ShahnoorSheikh Mohammad Shahnoor ID-12410224ID-12410224
Faisal AhmedFaisal Ahmed ID-12410209ID-12410209
Saiful Islam ShakilSaiful Islam Shakil ID-12410213ID-12410213
Md.AshrafuzzamanMd.Ashrafuzzaman ID12410219ID12410219

3.  Crawling & indexingCrawling & indexing
 algorithmsalgorithms
 Fighting spamFighting spam
Factors of Search EnginesFactors of Search Engines
Reference- “http://www.google.com/insidesearch/howsearchworks/thestory/”

4. 1.Crawling & Indexing
• Search starts with the web.
• It's made up of over 60 trillion individual pages.
• Google navigates the web by crawling.
• That means we follow links from page to page.
• The pages are sorted by their content and other factors.

5. Crawling & IndexingCrawling & Indexing
And by this ,engine keep track of it all in the index.

6. Names of some popular search EngineNames of some popular search Engine
 Google-Google-
 Bing-Bing-
 Yahoo-Yahoo-
 Ask-Ask-
 Aol.-Aol.-
 Mywebsearch-Mywebsearch-

8. 2.Algorithms2.Algorithms
• Programs & formulas are written to deliver the best results possible.
• Algorithms get to work looking for clues to better understand what
we mean.

9. As we search??
Spelling -Identifies and corrects possible spelling errors and provides alternatives.
 Auto complete -Predicts what you might be searching for. This includes understanding
terms with more than one meaning.
 Synonyms -Recognizes words with similar meanings.
 Query Understanding-Gets to the deeper meaning of the words you type.
 Search Methods -Creates new ways to search, including "search by image" and
"voice search."
Google Instant-Displays immediate results as you type.

10. Based on this clues we get relevant documents from the index

11. Ranking
 Site & Page Quality -Uses a set of signals to determine how
trustworthy, reputable, or authoritative a source is.
 Freshness -Shows the latest news and information.
 Safe Search-Reduces the amount of adult web pages,
images, and videos in your results.
 User Context -Provides more relevant results based on
geographic region, Web History, etc.
 Translation and Internationalization -Tailors results
based on our language and country.
 Universal Search -Blends relevant content, such as images,
news, maps, videos, and your personal content, into a single
unified search results page.

12. ResultsResults
The outcomes comes within 1/8th
seconds towards us

13. Robot Indexing DiagramRobot Indexing Diagram

14. 3.Fighting spam3.Fighting spam
It fights spam always 24/7.
To keep your results relevant.
The majority of spam removal is automatic.
Search Engine examine other questionable
documents by hand.
If it find spam, we take manual action.

15. Types of SpamTypes of Spam
1.1. Pure Spam -Pure Spam -Site appears to use aggressive spam techniques such as
automatically generated gibberish, cloaking, scraping content from other
websites, and/or repeated or egregious violations of Google's
Webmaster Guidelines.

16. 2.2. Hidden text and/or keyword stuffing-Hidden text and/or keyword stuffing- Some of the pages maySome of the pages may
contain hidden text and/or keyword stuffing.contain hidden text and/or keyword stuffing.
3. User-generated spam -Site appears to contain spam my user-
generated content. The problematic content may appear on forum
pages, guestbook pages, or user profiles.

17. 4.4. ParkedParked domainsdomains-Parked-Parked domains are placeholder sites with littledomains are placeholder sites with little
unique content, so Google doesn't typically include them in search results.unique content, so Google doesn't typically include them in search results.
5.5. Thin content with little or no added valueThin content with little or no added value..
6.6. UnnaturalUnnatural links tolinks to aa sitesite-manipulative links pointing to the site.-manipulative links pointing to the site.
7.7. Spammy free hosts and dynamic DNS providers.Spammy free hosts and dynamic DNS providers.
8.8. Cloaking and/or sneaky redirects-DCloaking and/or sneaky redirects-Displayingisplaying different content todifferent content to
human users than is shown to search engineshuman users than is shown to search engines
9.9. Hacked site.Hacked site.
1010..Unnatural links from a site-ThisUnnatural links from a site-This may be the result of selling linksmay be the result of selling links
that pass Page Rank or participating in link schemes.that pass Page Rank or participating in link schemes.

18. InitiativesInitiatives
 When necessary actions are taken , notification are sent toWhen necessary actions are taken , notification are sent to
the website owners.the website owners.
 In replyIn reply
 Site owners can fix their sites and let this know to theSite owners can fix their sites and let this know to the
desired search engine.desired search engine.

19. This is how search works
…………..
Questions & Answers????
Reference- “http://www.google.com/insidesearch/howsearchworks/thestory/”