Searching the Webby Lorrie Brazier

Revised by Paula Walton

What are search engines?• Special sites on the Web that help people

find information stored on other sites

• Tasks include:– Searching the Internet based on important

words– Keeping an index of the words they find and

where to find them– Allowing users to look for words or

combinations of words found in that index

How do they work?

• Use special software robots (called spiders) to build lists of words found on web sites– Spiders build lists by “web crawling”, i.e.,

spider travels through sites, indexing the words on the pages and following every link within the sites

– Spiders take a web page’s content and create key search words that enable online users to find pages they’re looking for

What is a meta tag?

• Allows the owner of a page to specify key words and concepts under which the page will be indexed

• NOTE: spiders will correlate meta tags with page content, rejecting the meta tags that don’t match the words on the page

What is robot exclusion protocol?

• Tells spiders not to index the words on the page nor to follow the links on the page

• Embedded into meta tags created by the author of the web page.

Indexing Pages

• A way of sorting or organizing keywords.

• Purpose: allows information to be found as quickly as possible

• A search engine stores the word, the URL, and assigns a weight to each entry, with increasing values assigned to words as they appear near the top of the document, in sub-headings, in links, in the meta tags, or in the title of the page

Building a Search

• User must build a query and submit it through a search engine

• Use Boolean operators to refine searches– AND– OR– NOT– Quotation Marks

Future Searches1. Literal searches—looks for words or

phrases exactly as they are entered; defined by Boolean operators

2. Natural-language queries—allows user to ask a question (ex: Ask.com)

3. Concept-based searches—will find other pages you may be interested in based on the words and phrases you search for using statistical analysis (in development stage)

Popular Search Engines

• AltaVista •Metacrawler

• Dogpile •Northern Lights

• Go •WebCrawler

• Google •Yahoo

• Hotbot •MSN (Bing)

• Looksmart •Lycos

Top Five Tips for Searching1. Use double quotation marks (“ ”)

around phrases to ensure they are searched exactly as is (Example: “North Dakota”).

2. Type keywords and phases in lower case to find both lower and upper case versions. Typing capital letters will usually return only an exact match. (governor retrieves both governor and Governor).

Top Five Tips for Searching

3. Put your most important keywords first in the string.

4. Use the plus (+) and minus (-) signs in front of words to force their inclusion and/or exclusion in searches. (Example: +Nevada –gambling)

Top Five Tips for Searching

5. Learn and use Boolean searches. Always enclose OR statements in parentheses, but do not use parentheses with AND statements. Example: (college OR university) AND “financial aid”

Top Five Tips for Searching

Final Note: Become very comfortable with at least two search engines. Print out their operating tips and know the limitations that can occur in each. It will save you a lot time!

Special Information

Downloading large files & music from the Internet takes up a lot of bandwidth & time. *The best time to do this is late in the evening & early in the morning.During normal business hours, (between 8:00 a.m. & 5:00 p.m.) large businesses are using most of the bandwidth.