1. Some Popular Portals Yahoo! : www.yahoo.com
Portals to the World from the Library of Congress:
AltaVista:

5. Search Engines?
A search engine is a web site that uses software to browse the Internet.
A search engine will retrieve a listing of World Wide Web sites related to the key words you specify.

6. How Search Engines Work
Read pages they find on the web (spider)
Store text in an “index”
When you search, they look for pages with matching text
Other factors involved in “ranking” those pages, such as “link popularity”

7. Search Engine INdexing
Computer-driven search tool
Website owners submit web address of their homepage for inclusion in the database
Robots periodically spider the Web, detect the homepage and proceed to scan every page in the entire website
(The first words on the homepage appear as the ‘result’ the user sees in the search engine)

8. Search Engines Crawler-based Search Engines Human-based Search Engines
“Spiders” or “Crawlers” visit websites and some of their pages periodically, and adds to index
Scans links and adds them to their index
Returns the information to the index or catalog
Search engine software sifts the index and ranks in relevant order
Human-based Search Engines
Mixed
Focused Crawlers: LawCrawler ( Part of the Fedlaw service which also has a targeted directory.
sponsored by the APA

9. Directories Vs Search Engines
When should you use a directory?
When you have a broad topic
When you want experts to recommend sites
When you want to avoid irrelevant sites
Examples topics:
Disabilities
Civil War
Welfare

10. Directories Vs Search Engines
When should you use a search engine?
When you have a narrow topic
When you are looking for a specific website
When you want to search for a file type or language
Examples:
Americans with Disabilities Act
Battle of Gettsyburg
Welfare to Work

11. Start Your Search Engines Here
Google
AllTheWeb
Yahoo
MSN
Why? See:

12. Other Search Engine Types
News Search Engines
Multimedia Search Engines
Metacrawlers
Kids Search Engines
Regional Search Engines
Scientific Search Engines

13. Top Search Engines & Directories
Google
Yahoo!
AllTheWeb
AltaVista
Open Directory
MSN Search
About
Ask Jeeves
WiseNut
HotBot
LookSmart
Teoma
AOL Search
iLOR

14. Google
Google is the undisputed leader in search engines, with the largest database and highly relevant results
Uses an algorithm based on site popularity
The more inbound links pointing to a particular site from another site Google thinks is worthwhile, then that site will receive a higher page rank in the results
Wary of minimising advertising - no frills design, nice clean look and no pop-up ads

15. AllTheWeb & AltaVista
AllTheWeb used to be a Norwegian search engine FAST and for a while was one of the Web’s best kept secrets
AltaVista was the first search engine in 1995 and was THE search engine before Google existed
Recently, Overture acquired FAST and AltaVista
This year, Yahoo! acquired Overture and Inktomi, making Yahoo! the largest network of major search tools on the Internet
AllTheWeb & AltaVista’s future are now unknown, as many results are simply retrieved from Yahoo

16. Open Directory & Ask Jeeves
Open Directory Project is the largest humanly-compiled search directory on the Web
As each website is considered for inclusion by a human (many don’t make it) - quality is assured
Ask Jeeves uses special natural language technology, so the user can ask a complete question instead of inputting only a few words
It then searches its own database and supplements this with results from Teoma
Ask Jeeves is popular with young Web users

17. Understand Limitations of Search Engines
Search “spiders” or “crawlers” do *not* crawl in real time
Lag times getting info to the index vary by search engine
If a website is not submitted to the search engine it won’t be crawled
Not every page from a website is crawled
A webmaster can choose to not have a page crawled
Formats like PDF, Flash, Zip files, executable programs, and others cannot be searched
The “Invisible Web”
If a webpage has no links pointing to it from another page the crawler can’t find it.

18. Evaluating Web Sites Continued…
Can you find this news reported on a legitimate news website?
Who is the sponsor of the website?
Are there inconsistencies or inaccuracies in the information?
If an organization is mentioned by name, does the organization have any related information on this website?

19. Meta Search Engine
Searches more than one search engine simultaneously (often up to fifteen)
Each meta search engine normally searches a different combination of search engines
Simultaneous multiple engine searching saves the user lots of time
But meta search engines only skim the surface of each engine’s database and sometimes lack depth when searching for results

20. Top Meta Search Engines
Kartoo
Turbo 10
Dogpile
Mamma
Red Hot Chilli
Meta Eureka
Web Taxi
Vivisimo
ixquick
iBoogie
Metacrawler
Supercrawler
Search.com
Query Server

21. Kartoo & Turbo10
These search tools cluster sets of results on similar topics and display them on the side frame
Kartoo is arguably the funkiest search facility on the Web, displaying results as a visual mind map
There’s a basic and expert version for searching
Turbo10 is unique because it has a long list of specialist databases on specific subjects
Searches the Deep Net (others rarely go there)
Users can also tailor their searching by selecting unusual databases of their own choosing

22. Vivisimo, Dogpile & Mamma
Vivisimo also uses clustering technology and allows users to choose their own search engines
Dogpile was one of the earliest meta search engines and remains very popular today
It’s major advantage lies in its search engines: Google, Yahoo!, Ask Jeeves, Teoma, About etc.
Canadian-based Mamma began in 1996 as a Masters thesis, arguably the first meta search
Today it is a well respected search tool and like Dogpile, searches the Web’s top engines such as Google, Open Directory, Teoma and others

23. Image ( + Meta) Searching
Although pictures on websites often appear neatly embedded amongst text, each image needs a unique URL, allowing picture searching
Google’s image search is one of the best on the Web, partly because of the size of its database
There are also excellent picture meta search engines: iBoogie, Dogpile, ixquick and 1Banana
picsearch is solely a picture search engine and markets itself as family and user friendly

24. Language Translation Google and AltaVista offer language translation
Google will allow you to translate a foreign language website or page and even allow you to link to the translated page from another website
AltaVista uses Babel Fish for its translation and you can also translate blocks of text
Some of the best websites on Bertolt Brecht and his Epic Theatre are actually in German, so this is an example of where translation tools are worthwhile if you speak another language

25. Useful Reference Tools
You can find free dictionaries online, such as Merriam Webster, Oxford, Macquarie, Cambridge and Dictionary.com
Most dictionaries also have a thesaurus tab
The meta dictionary OneLook simultaneously searches nearly 1,000 generalist and specialist dictionaries!
Some of the weirdest words out there are at the Strange and Unusual Dictionaries website
Or visit RyhmeZone’s Rhyming Dictionary & Thesaurus for a bit of fun!

26. More Reference Tools
If looking for the origin of a phrase or saying, try Brewer’s Dictionary of Phrase and Fable
There’s also the ClichéSite or the Hutchinson Dictionary of Difficult Words
Free encyclopaedias include Encyclopedia.com, Columbia, Encarta (partly free), Wikipedia, Hutchinson & the 1911 Encyclopaedia Britannica considered by many to be the best edition ever!
Way Back Machine has been archiving large portions of the Web since 1996, so if a website has suddenly disappeared, search for it here!

27. The Invisible Web
Web information that does not get indexed by the major search engines.
Hidden mostly in databases or have robot.txt file attached
Data created on the fly from the backend (cgi-bin, etc)
More than ¾ of information on the Web is part of the IW.

28. The Invisible Web – 4 Types
Opaque: search engines choose not to index
The Private Web: password protected
The Proprietary Web: registration required (either fee or free)
The Truly Invisible Web: can’t search certain file formats and databases
OPAQUE: Depth of crawl is limited – sometimes for cost reasons
Frequency of crawl is limited - pages that change every day are affected
Maximum Number of Results
PRIVATE: password protected, robots files disallows spiders access, “noindex” meta tag prevents access
PROPRIETARY: either free or fee registration is required. Examples are The New York Times, The Well, The Wall Street Journal Interactive Edition.
TRULY INVISIBLE: file formats like PDF, Flash, Shockwave, etc.; dynamically generated web pages

29. Examples of the IW Online telephone and address databases News engines
Professional look-up services (AMA)
Movie and Book Reviews
Education databases (ERIC)
Medical databases (Medline)