THE INTERNET:

A GUIDE TO

WORKING SMARTER

WORLD WIDE WEB SEARCH TOOLS
There are several search tools available for finding information on the World Wide Web. They include Subject Directories, Search Engines, Specialized Databases, Subject Guides, and Meta Search Engines. One of the keys to effective searching is determining what tool will best answer your question.

SUBJECT DIRECTORIES
Directories are made up of selected Web pages that are evaluated and organized into hierarchical categories. They may also include Specialized Databases and Subject Guides. Web directories are compiled either by humans or computers that follow preset selection criteria and link to pages of high quality. Subject directories are time consuming to compile and maintain and tend to be smaller databases. Because they are smaller databases, the scope of the results will be smaller, too. Web directories are most useful when browsing broad subject areas, though it can be difficult to find topics that are not easily categorized. The lack of controlled vocabulary within and among directories can make browsing difficult and time consuming. To ease this problem, most directories offer keyword searchable indexes. Some Subject Directories include a web search engine along with their subject directory. Yahoo is the oldest and most popular directory on the Web, listing over one million sites. One hundred fifty editors categorize the Web for Yahoo. Other Subject Directories include:

Internet Public Library Reference Center
http://ipl.sils.umich.edu/ref/
Looksmart
http://search.looksmart.com
Open Directory
http://dmoz.org

USING SUBJECT DIRECTORIES
To use a directory first identify the broadest subject meeting your information needs. Follow the links until you reach those closest to your desired subject. Bookmark relevant sites to review later as you move through the links.

EXERCISE 1
Go to Yahoo, http://www.yahoo.com, and browse through the category Health. Notice that the topic Health is broken down into categories like Alternative Medicine, First Aid, and Travel Health and Medicine. Click on Medicine and notice that this category covers topics from acupuncture to wound care. Click on the topic Pediatrics and scroll down to the category section and click on Sleep Medicine. Find the topic Sudden Infant Death Syndrome and click on that. Click on the link to the American SIDS Institute and browse the website.

SEARCH ENGINES
Internet Search Engines are giant indexes that enable keyword searching. Search engines use computer programs referred to as robots or spiders that "crawl across the Web" to find information that matches your keywords. Indexes are much larger than directories and are more current. Search engines vary in size, frequency of updating and search options. While they all rely on spiders to collect and index information, each individual search engine uses its own interface and criteria for matching searches to documents. There is currently no common standard that search engines follow. They each operate a little differently and will retrieve unique documents with limited overlap. This is one argument for using more than one search engine, especially when you are having difficulty locating the information you desire.

Some Search engines use link analysis as well as popularity rank results to determine the quality of a page. For example, Google uses an algorithm called Page Rank which calculates the quality of a page by the number of pages that link to it. In other words, it considers a link from one page to another as a vote for that page. The more links to that site, the more votes it receives and ultimately the more relevant it is according to Google. Google also takes into consideration the quality of the site casting the vote. If it is what Google determines to be a major site like, ABC, NBC, CBS, CNN, etc, those votes are weighed more heavily than less popular sites. This type of link analysis could be compared to the number of references that a review article sites.

Major Search Engines include:
All the web: http://www.alltheweb.com
Alta Vista: http://altavista.com
Google: http://www.google.com
Teoma: http://teoma.com

Search engines are most useful when you have a very specific subject to research. To keep up on the latest news regarding search engines go to Search Engine Watch (http://www.searchenginewatch.com), Search Engine Showdown (http://www.searchengineshowdown.com) or Search Engine Colossus (http://www.searchenginecolossus.com/).

USING WEB SEARCH ENGINES
To perform a keyword search, you will need to analyze your topic, choose a search engine and then formulate a search statement. Compose a list of synonymous terms and distinctive phrases. Use several different search engines and then compare the results, which can be very different. Use Phrase Searching, Boolean Searching, and Truncation where appropriate. Check the Help file for the search engine you choose to make sure that they support these types of searches. Check the Help file often for any changes or enhancements to the search engine you are using.

EXERCISE 2
Go to Google, http://www.google.com, and type in "sudden infant death syndrome" in the subject line and click on Search. Notice how many documents are retrieved. Take a look at some of the sites retrieved.

POWER SEARCHING TECHNIQUES
When using search engines to search the Internet, often thousands of documents are retrieved. To limit/focus a search and retrieve more relevant documents, power searching techniques are used. These include Phrase Searching, Boolean Searching, Nesting and Truncation. Check the Help file for techniques available for the search engine you are using.

PHRASE SEARCHING
When inputting a keyword search with more than one term in the search statement, consider phrase searching. Entering a phrase enclosed within quotation marks signals the search engine to search for that specific phrase. If you enter multiple words and omit the quotation marks, the search engine looks for references that include any of the words regardless of whether they are related.

EXERCISE 3
Go to Google, http://www.google.com, and type in "sudden infant death syndrome" (enclose the phrase in quotation marks) in the subject line and click on Search. Look for any differences in the search results and compare to your last search. What are the differences?

BOOLEAN SEARCHING
Boolean Searching refers to a form of logic applied to a search. The Boolean operators are AND, OR, NOT. Some search engines require these operators to be capitalized. It will be useful to always use capitals. These terms may vary from search engine to search engine, but the ideas are the same. Check the Help file if in doubt.

• AND narrows a search. It intersects two sets and is used to reduce results.
• OR broadens a search. It is the union of two sets and is used to increase results.
• NOT narrows a search. It is the exclusion of one set and is used to reduce results.

EXERCISE 4
Go to Excite, http://www.excite.com/, and in the subject line type "sudden infant death syndrome" AND prevention. Browse through the documents retrieved and look for the SIDS Network home page. Click on this link and see if you can find information on SIDS and smoking.

NESTING
When you have a search statement that contains more than one type of Boolean operator, use parentheses to combine synonymous terms.

The search statement: Cancer AND (teen youth adolescent) signals the search engine to look for any of the terms within the parentheses and then combine the results with the term outside of the parentheses. (Note: some search engines do not require the OR operator between the search terms. Check the Help file if in doubt.)

EXERCISE 5
Go to Northern Light, http://www.northernlight.com/. In the subject line type (infant OR newborn) AND "sleep disorders". Click on the link to the most relevant site you find and browse the website.

TRUNCATION
Truncation allows you to search on the root of a larger word. Most commonly, an asterisk (*), but sometimes a question mark (?), is used to signal the search engine to look for the root of the word and all of the possible variations.

For example, Child retrieves references with the word child in it. Child* or Child? retrieves references with the word child in it as well as child's, childish, childishly, childishness, children, children's, childhood, childlike, etc.

EXERCISE 6
Go to Webcrawler, http://www.webcrawler.com, and in the subject line type in "sleep disorders" AND child*. Examine the results. Notice that Webcrawler lists directory search results and then also Web search results. Notice under Web results, there is an option to show link summaries or just the titles.

META SEARCH ENGINES
Search engines vary in size and often retrieve different results. Using a Meta Search engine is a quick way to determine which search engines will yield the best results. Simple searches work best in Meta Search engines. Meta Search Engines search several search engines at the same time but most only retrieve the top 10-50 results from each search engine. Power searching techniques may not be properly processed or available. One Meta Search engine, Ixquick, http://www.ixquick.com/, knows which search engines can support Boolean, Phrase, Truncation, Nesting, etc, searching. It will only send your search statement to search engines that can process it properly.

USING META SEARCH ENGINES
When using Meta Search Engines you enter the search statement one time and it is sent to several search engines simultaneously. The results are then blended together. They generally only catch about 10% of search results in the search engines they cover. Some examples of Meta Search Engines include Dogpile, Mamma, MetaFind and Ixquick.

EXERCISE 7
First go to Ixquick, http://www.ixquick.com/, and in the subject line, type in SIDS. Take a look at the results. Can you tell which search engines were searched? Next, go to Dogpile, http://www.dogpile.com/index.gsp, and perform the same search. Notice the differences between the two Meta Search Engines.

SPECIALIZED DATABASES
(THE INVISIBLE OR DEEP WEB)

The Invisible Web is made up of content that Search Engines either cannot or will not index. It consists of searchable databases, password-protected sites and documents that are hidden by firewalls. These types of websites are inaccessible to the spiders, robots, and WebCrawler programs that are used to compile indexes for search engines. They can index their location, but not the information they contain. These pages often lack links that point to a page that the programs can follow, or the page may be made up of data types that search engines are not programmed to index. Specialized Databases are similar to Subject Directories as they are often organized by subject categories and evaluated and organized by humans rather than computer programs. The documents found by using these specialized databases are referred to as the Deep or Invisible Web.

Subject Directories that provide access to the Invisible Web include:

Invisible Web: http://www.invisibleweb.com
Complete Planet: http://www.completeplanet.com
Librarians Index to the Internet: http://www.lii.org
The Invisible Web Directory: http://www.invisible-web.net
Infomine: http://infomine.ucr.edu
Academic Info: http://www.academicinfo.net

Examples of Specialized Databases covering Health and Medical include:

Combined Health Information Database: http://chid.nih.gov/simple/simple.html
Health wise: Go Ask Alice http://www.goaskalice.columbia.edu
Mayo Clinic: http://www.mayoclinic.com

SPECIALIZED DIRECTORIES/SUBJECT GUIDES
Specialized Directories or Subject Guides are collections of general Web pages compiled by experts in their field. These directories are often referred to as distributed subject trees. They rely solely on volunteers who are knowledgeable in a given subject area to classify and index the Internet. The subject trees are not comprehensive in scope and provide no authority control.

Examples of Specialized Directories include:

AboutCom
http://www.about.com

WWW Virtual Library
http://www.vlib.org/overview.html

© Florida AHEC Network, 2003