web searching and ppt. searching for information on the web goals: –decrease number of search...

Web Searching and Web Searching and PPTPPT

Web Searching and Web Searching and PPTPPT

Searching for Information on the Web

Goals:– Decrease number of search results

– Increase number of relevant results

Method:

Structured vs keyword searching– Use any of several search tips and commands

– Search engines vary in terms of the commands they support. Just because one does not find it does not mean its not there.

Different search engines are different. All have “help”

http://www.google.com/intl/en/help/basics.html http://search.yahoo.com/web/advanced http://help.ask.com/en/docs/about/adv_search_tip

s.shtml

http://www.dogpile.com/info.dogpl/search/help/faq.htm?r_fcid=416&r_fcp=top

Search Command Options

“Search engine math”– Basic tips to improve your search

Field searching– Search for terms within specific parts of the document

(e.g., title)

Boolean and other advanced commands (e.g., AND, OR)

Search assistance and display features– Features of the engines, themselves

Search Engine Math

Include term (+)– To ensure word is included in search

e.g., +camping +Arkansas

Exclude term (-)– find pages that have one word on them, but not another

word

e.g., +apples -computer

Phrase (“_”)e.g., “social psychology”

Search Engine Math II

Match any term– Automatic in some, option on others– Match all terms– Use + or menu; automatic at some (google)

Truncation/Wildcard (*)– To find all forms of a word– archaeolog* (-y, -ical, -ist)– Stemming: finds all forms based on the stem

automatically– Automatic at google

Field Searching and Limiting

Title search -- to search for words w/in titles of web pagese.g., +title:elephant +species

Site search -- to search w/in documents on a specific sitee.g., domain:memphis.edu psychology

URL search -- to search within the text of URLse.g., url:memphis.edu

Field Searching and Limiting II

Link search -- to search for pages that link to a particular page or domaine.g., link:psyc.memphis.edu/students/../

Limit by language– Search for documents in a particular language

Limit by date pages were created or modified Limit by type

– Engineering filetype:ppt

Boolean Commands

AND returns pages containing all search terms joined by AND e.g., Mars AND planet AND life

OR returns pages containing any or all search terms joined by OR e.g., “bed and breakfast” or inn

NOT returns pages containing the first but not the second terme.g., clinton NOT lewinsky

Boolean Commands II

NEAR returns pages containing keywords near each other on the pagee.g., psychology NEAR history

(distance can be specified . Alta Vista does this)

Nesting Boolean commands provides for complex queriese.g., psychology AND (social OR cognitive) . . . If no

parentheses . . .

(psychology AND social) OR cognitive

Combining Commands

Examples:– (cat* OR feline*) AND “endangered species”– +title:psychology +dream* -Freud*– “star trek” -voyager -“deep space nine” -“next

generation”

Works only if search engine supports each command, obviously

Search Assistance Features

Related Searches– Search engine provides related searches after a search

is complete

Find Similar– Provides ability to find other pages that seem similar

to those you like

Search Within– Do a second search within results already generated

Display Features

Ability to sort results by date (created or modified), with most recent documents listed first

Some search engines display the date page was created or modified

* Note: dates can be unreliable (gotten from server) Ability to increase the number of results that are

displayed Google use a patented algorithm for “search

order” display.

A Note about Meta-search Engines

Dogpile and MetaCrawler will allow many of these commands, but if the engine they are polling does not, you may end up with funky results

Sometimes, the syntax will be removed (e.g., Boolean operators)

At other times, however, they will become a keyword in the search (e.g., title:)

Specialty Search Engines

Catalog information particular to a narrow topic area

Pro: potentially more coverage versus the general search services

Con: don’t provide you the search options and flexibility of general search engines

A directory of search engines (general and specialty):www.beaucoup.com

Example

Compound interest quote

Checking things.

Not everything on the web is “correct” Not everything in print is “correct”. Often have to “check your facts…” http://timpanogos.wordpress.com/2006/07/22/

einstein-compound-interest-does-not-compute/

Sources

Understand the “trustworthiness” of the source. Credible publishers (webster) Probably okay Wikipedia reasonable but less reliable (many can

fix, but still many add/change). Blogs: often dubious

Ask why its there, what is their interest.