LIR 10: Week 10

Advanced WWW Topics

Class Announcements

• New features on Section 2904 Schedule

• Missing Homework

• Online Quiz due 11/16

• Another WWW directory recommendation:

The Internet Public Library http://www.ipl.org

Evaluating Search Engines

• Learn how your search engine finds documents on the WWW

• Find the best ways to search

Infopeople’s Best Search Tools Chart:

http://www.infopeople.org/search/chart.html

WWW Page Sources: How to Find Them

• Check web page title, section headings, menu or opening paragraphs. • Look near the top, bottom and navigational bar of the page.• Look for a description links anywhere on the page:

"About the ______ Association""About Us" “Mission Statement”

• For a author, check for links to his/her faculty or professional web pages. • Check for links to articles and publications by the person or organization. • Look for an address or phone number.• Check library catalogs, Internet search engines and magazine or newspaper

databases to see if the person or organization has published books or articles in the field.

• No source or author information? Be wary.• The webmaster or person who designed the web page is not necessarily the

one responsible for the content of the page.• Examine the URL

Deconstructing URLs

• URL= Uniform Resource Locator: the “address” of web documents

• Another way to discover the source of web documents.

• A domain is the main subdivision of internet addresses

• Check the last two or three letters after the final dot

• Backspace over the last section of the URL to find the main page of the site

• .edu, .gov, .mil, .ca, .us • .net, .org .com are

unrestricted• See ICANN | Top-Level

Domains (gTLDs) for full listings.

Internet Searching: Beyond the Basics

Metasearch Engines:

• Sends your keywords to several search engines at the same time.

• Return a single list of results from multiple sources

• “Source” engine identified

Search Engines

• Search for keywords- number of times within document

• Searches keywords from a single database of websites

• Each search engine searches a unique selection of web pages

• Results are ranked and sorted• Sends robots or spiders out to find new

websites

Metasearch Engines

• Transmits searches simultaneously to several individual search engines.

• Results gathered from all search engines queried.

• Meta-search engines do not search a database of Web pages.

• Search terms are sent to the databases maintained by traditional search engines.

Metasearch Engines

Pros:• Retrieve a relatively small

number of relevant results

• “A wider net”– helpful when you’re not finding sufficient information using regular search engines.

• Provide an overall picture of what’s available on the WWW

Cons:• Limited to simple queries• Limited search fields• “A shallow net”--generally

queries 10% of search engine results

• Includes sponsored links• May not include Google

results

Other Sources of Information on the Internet

• The “hidden” Internet

• Newsgroups and Listservs

• Databases

• News search engines

The “Hidden” Internet:Or, the Invisible Web

It’s not a secret:The Hidden Internet refers to what is not retrieved in the search results of most commercial search engines.

Most of the invisible web is made up of the contents of thousands of specialized searchable databases that you can search via the WWW.

The Hidden Internet, cont.

• These “hidden” databases are often produced by very reliable sources:

• Universities• Libraries• Associations• Businesses• Government agencies

from the US and abroad.

Invisible Web Search Tools

• http://invisible-web.net

• http://www.lii.org

• http://www.completeplanet.com

• http://www.freepint.com/gary/direct.htm(Caveat: searching the last site is challenge!)

Other Ways to Find the Hidden Internet

• Search Google or other search engines for databases. For example:

Tree database

Homeopathic database

• Search Google or other search engines for web directories. For example:

Civil War web directories

Genealogy web directories

Invisible Web Search Examples

• Searching invisible-web.net

• Searching Google for Databases

• Searching LII

Newsgroups and Mailing ListsNewsgroups

• Worldwide bulletin board system accessed through the Internet.

• Contains tens of thousands of forums (newsgroups).

• Groups focus on wide range of topics, accessible to anyone and everyone.

• Every newsgroup is identified by a segmented title indicating the group's subject matter.

• Format is “bulletin board” style: original and follow-up postings, also known as "articles".

• Not subscription based.

Mailing Lists• Term for automated mailing list

distribution systems.• People sharing an interest

"subscribe" to discussion lists • Subscribers' contributions

distributed to the entire subscriber base via e-mail

• Commonly used by discussion groups.

• Mailing lists can focus on any type of discussion

• Subscription-based.

Newsgroups and Mailing Lists

Pros• Good for locating

professional discussions.

• Interactive, questions welcome.

• Collaborative• Alternative voices• Cyber-networking

Cons• Unmoderated or

lightly moderated forums

• “On the Internet, no one knows you’re a dog.”

• Can be difficult to search

Newsgroups and Mailing Lists

• Accessible mailing lists by Catalist: http://www.lsoft.com/lists/listref.html

• Google groups (the Usenet):http://groups.google.com

• Usenet history: http://www.ibiblio.org/usenet-i/• Yahoo groups:

http://groups.yahoo.com• Topica lists: http://lists.topica.com/• About.com forums: http://www.about.com

Other Ways to Find Collaborative Sources

• Search Google or other search engines for forums. For example:

PDF forums

• Search Google or other search engines for discussion groups. For example:

Gardening discussion groups

Newsgroup and Mailing List Search Examples

• Google Groups (Usenet)

• Catalist Listserv search

Weblogs or Blogs

• Online journals, updated often

• News-oriented• Contain commentary

and links• Personal or

professional focus

Pros:• Alternative sources• Constantly updated• Wide range of topics

Cons:• Difficult to search• Too much information• Reliability of authors

Weblog Sources

• Google Directory:http://directory.google.com/Top/Computers/Internet/On_the_Web/Weblogs/

• DMOZ Weblog listing:http://dmoz.org/Computers/Internet/

• IPL Blog Page:http://www.ipl.org/div/blogs

• Search Google or other search engines for weblogs or blogs. For example:

Gardening weblogs

Final Advice About the Internet

Be careful out there!

Next Week’s Homework

• WWW Assignment 2

• Online Quiz: http://online.santarosa.edu/testbank/?5714

• Final Project due

• Final is next week: bring a Scantron form!