Transcript Introduction to Web Browsers and Basic Search Strategies

Introduction to Web Browsers
and Basic Search Strategies
Using Search Engines
Davina Pruitt-Mentle
EDUC 478
Outline
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History (WWW & Internet)
Search tools
Search Engines vs. Subject Directory
Meta search Engines
Steps for Searching
Effective Strategies
Narrow or broaden a search?
Wildcards
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Internet History
• Internet made up of thousands of networks
worldwide
• No one in charge of Internet - No governing
body
• Internet backbone owned by private
companies
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Looking at the Net
Taken from: http://www.cio.com/WebMaster/sem2_net.html
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Understanding the Map
• Computers use TCP/IP to communicate
(Transmission Control Protocol/Internet
Protocol)
• Computers use client/server architecture
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Internet Providers:
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Research and Educational Institutions
Government and Military Entities
Businesses
Private Organizations
Commercial Providers
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Internet Protocols
• Email (Simple Mail Transport Protocol)
• Telnet (Login to remote host computer)
• FTP (File Transfer Protocol) - transfers
files between server and client
• HTTP (HyperText Transfer Protocol)
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History
• WWW or Web or W3 includes all information,
text, images, audio, video, and computational
services that are accessible from the internet
• July 8, 1999 Nature - approximately 800 million
pages of publicly accessible information(1)
• Web continues to grow, tripling in size over the
past two years(2)
(1) Steve Lawrence & C. Lee Giles, “Accessibility of Information
on the Web,” Nature 400 (July 8, 1999), 107
(2) OCLC Office of Research, “June 1999 Web Statistics” Web
Characterization Project
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WWW
• System of Internet servers that support
hypertext to access several Internet
protocols on a single interface
• Almost all protocols accessible on Internet
are accessible on web (email - FTP - Telnet
- etc)
• In addition, WWW own protocol:
HyperText Transfer Protocol
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HTTP
• Hypertext - means of information retreival
• Contains links that connect to other
documents
• Links selected by user
• Virtual “web” of connections
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HTTP (cont)
• Produce HTTP through HTML
• HyperText Markup Language
• Way of writing or creating with “tags”
added to tell information
– i.e. <b> Bold </b> yields Bold
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More History
• Internet initially conceived in 1989 by Tim
Berners-Lee at CERN (European Particle
Physics Lab in Switzerland)
• Needed a wide variety of information to be
shared and distributed to many different
computers and platforms
• “Universal readership”
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Web Popular Because:
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Easy to use
Easy to navigate
Combines words, graphics, sound, video
Easy to Publish
Plethora of information
Reach larger audience
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Summary: Web vs. Internet
• What is the relationship between the web
and the Internet?
• The Internet contains physical components
– computers
– networks
– services
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Web vs. Internet
• The Internet connects thousands of
computers across the world, but it is the
web that allows communication to occur
• Web - abstraction and common set of
services on top of the Internet
• Web - set of protocols and tools that let us
share information with each other
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Directed Search Strategies
Davina Pruitt-Mentle
July Design Institute
July 20, 2000
How Do I Find
Information on the Internet?
• Join an email discussion or USENET
newsgroup
• Go directly to a site if you have the address
• Browse
• Explore subject directory
• Conduct Search
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How Does Information Get
Indexed by the Search Tools
• A publisher of a web page can register the
site with the search engine or directory
• Database collects data autonomously
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Browsers
• Netscape Navigator (Communicator)
– Product of Netscape (Now owned by AOL)
– Originally was dominant
– Multi-platform (all operating systems)
• Internet Explorer
– Product of Microsoft
– Current Dominant Browser
– Not available for all operating systems
• Browser compatibility problems can cause
web page problems
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Netscape Search
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Netscape Search
• 1: Access to different
search engines
• 2. Type words or
phrases into text
entry box
• 3. Click Button
• 4. Preserve favorite
search engine
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Internet Explorer Search
•Separate Panel In Browser
•Uses MicroSoft Network
search
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Internet Explorer Search
• Direct access to only Microsoft Network’s
search engines
• Allows easy access to different types of
search
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Web pages
People
Businesses
Maps
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Internet Keywords
• Type straight in location bar of
Netscape/Explorer
• Simple words instead of URL (uniform
resource location)
• Words tie to websites
• Can be tied to language preference
• Example: Typing in maryland converts to
http://www.state.md.us/
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Know your URL’s
• “Address” of a file on the Internet
• Contains type of protocol followed by the
computer name, directory and file name
• Examples
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http://www.capecod.net/Wixon/wixon.htm
gopher://gopher.boombox.micro/
ftp:// wuarchive.wustl.edu/pub/windows/psp3.zip
mailto:[email protected]
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Anatomy of a Web Address
• protocol://host/path/filename
See handout “Anatomy of a Web Address”
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Two Basic Approaches to
Searching
(although not really “basic”)
• Search Engines
• Subject Directories
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Search Engines vs. Directories
Directories
Search Engines
• Human aided, organized list
• May be general or subjectspecific
• May be able to “search”
directory
• Computer built index of
information on web
• More inclusive
• Used to find specific resources
• Searchable by keyword
• Excessive “hits”
• Every page of a Website is
indexed
• Better for general searches, but
can be used to find specific
information
– Google - general
– NetTech Educational Technology
Coordinator Website - subject
specific
• User has control of browsing
• Fixed vocabulary
• Links go to Website home
pages only
• Better at general searches
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What are Search Engines?
• Designed to assist you in searching through
the enormous amount of information on the
Web
• No single search tool has everything
• Each engine is a large database which
utilizes different search techniques and tools
(spiders or robots) to build indexes to the
Internet (some also utilize submissions and
administration)
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Which Search Engine?
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Yahoo
Altavista
Excite
Google
NorthernLights
Hotbot
Infoseek
See Handout - “The Little Search Engine that Could”
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How to Choose
Consider
• Size of the database (# of URLs)
• Currency of the database (updates)
• Search interface
• Help screens
• Search features
• Results listed (# of documents retrieved)
• Relevance of results
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More About Search Engines
• Searches for matching terms (keywords or
several keywords)
• Results “ranked” by relevancy (for some)
• Can search by
– subject or category
– keyword
• Learn about each search engine’s
description, options, and rules and
restrictions
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GO TO
http://www.google.com/help.html
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 Searches for exact matches
 Try different versions of your search term
 Example: “Boston hotel” vs. “Boston hotels”
 Rephrase query
 Example: “cheap plane tickets” vs. “cheap
airplane tickets”
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• Automatically places “and” between words (expands search)
• To reduce search –
– add more terms in original search
– refine search within the current search results. (adding terms to
first words will return a subset of the original query)
• Exclude a word by using a – sign
– Example: to search bass but not speaker  bass –speaker
• Does not support “or” operator
• Does not support “stemming” or “wildcard” searches
• Not case sensitive
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• Finds street maps
– Just enter a U.S. street address, including zip
code or city/state into the search box
– Google recognizes query as a map request
Try your address
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Phrase Searches and Connectors
• Phrase Searches are useful when searching for
famous sayings or specific names “Gone with the
Wind”
• Phrase Connectors are recognized
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Hyphens
Slashes
Periods
Equal signs
Apostrophes
• Example: mother-in-law
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Stop Words
• Stop words are ignored
• These rarely help narrow and slow down search
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http
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certain single digits
certain single letters
• to include stop words use [space]+
• Example
– Star Wars, Episode 1  Star wars episode +1
– OS/2  OS/ +2
***don’t forget the space before the + - signs
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How to Interpret Results
See Handout
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 Combines in one search a very large fulltext Web-page database (~160 million
pages) with over 5,400 searchable full-text
published (print) journals and an array of
online news resources
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 You may access both relevant web-pages
and relevant journals and news releases
 Tagged
 WWW like other search tools or
 Special Collection (published, fee-for-viewing
journal articles or other publication)
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GOTO
http://www.northernlight.com/docs/specoll_help_overview.html
• To obtain an item from the Special
Collection:
 Click on link
 Decide if you are willing to pay fee
• Page provides citation so you can locate
publication in library
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Unique Folders Approach
• Results grouped in folders listed at left
• Folders dynamically generated by search results
– From a controlled vocabulary
– Similar to library cataloging
– Not fixed like subject directories
• Click on any folder to refine or further focus
search
• Sub-folders allow you to further “zero in”
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Four Types of Folders
• Subjects (baseball, desserts)
• Source descriptors (commercial, personal,
magazines, databases)
• Types of documents (press releases, product
review, maps)
• Languages (major Romanized languages
only)
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Approaches to Searching
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Basic Search
Power Search
Industry Search
Investext Search
News
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Basic Search
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Http://www.northernlight.com
From Home Page
Allows Boolean logic
Phrase in “ ”
Truncation (*for many characters or % for 1
character)
• + requires, - excludes
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Power Search
• Http://www.northernlight.com/power.html
• Combines ALL basic search features in one
search
• Limits to major language or country
• Can select subject or document in advance
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Industry Search
• http://www.northernlight.com/business.html
• All features of basic search
• Can limit by date range or industry-based
subject category
• Default is ALL industries
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Investext Search
• http://www.northernlight.com/investext.html
• Search or browse thousands of investment
research reports written by expert analysts.
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News Search
• http://www.northernlight.com/news.html
• Allows on-line news searches
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“Meta” Search Tools
• Multi-threaded search engines
• Allows access to multiple databases
simultaneously or via a single interface
• (-) Do not offer the same level of control over
search interface and logic as individual engines
• (+) Fast
• (+) Improvements
– Results sorted by site used for search, or location of Website
– Able to select search engines to include
– ability to modify results
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Popular Meta-Search Engines
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Dogpile
Metacrawler
Profusion
SavvySearch
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Subject-Specific Search Engines
• Do not index entire web
• Focus within specific Websites/pages within
defined subject area, geographical area, type
of resource
• Specialized search - depth rather than breath
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Selected Subject-Specific Engines
Companies
• Companies Online (http://www.companiesonline.com/)
• Hoover's Online (http://www.hoovers.com/)
• Wall Street Research Net (http://www.wsrn.com/)
People (E-mail and Phone)
• Bigfoot (http://bigfoot.com/)
• WhoWhere? (http://www.whowhere.lycos.com)
• Yahoo! People Search (http://people.yahoo.com/)
• Switchboard.Com (http://www.switchboard.com)
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Selected Subject-Specific Engines
Images
• The Amazing Picture Machine
(http://www.ncrtec.org/picture.htm)
• Lycos Image Gallery
(http://www.lycos.com/picturethis/)
• WebSeek
(http://disney.ctr.columbia.edu/webseek/)
• Yahoo! Image Surfer (http://ipix.yahoo.com/)
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Selected Subject-Specific Engines
Jobs
• Hotjobs.com (http://www.hotjobs.com/)
• Monster.com (http://www.monster.com/)
• The Riley Guide (http://www.rileyguide.com/)
Games
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CNET Gamecenter.com (http://www.gamecenter.com/)
Games Domain (http://www.gamesdomain.com/)
Gamesmania (http://www.gamesmania.com/)
GameSpot (http://www.gamespot.com/)
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Selected Subject-Specific Engines
Software
• Jumbo (http://www.jumbo.com)
• Shareware.com (http://www.shareware.com)
• ZDNet Downloads (http://www.zdnet.com/downloads/)
Health/Medicine
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Achoo (http://www.achoo.com/)
BioMedNet (http://www.bmn.com/)
Combined Health Information Database (http://chid.nih.gov/)
Mayo Clinic Health Oasis (http://www.mayohealth.org/)
Medical World Search (http://www.mwsearch.com/)
OnHealth (http://www.onhealth.com)
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Selected Subject-Specific Engines
Education/Children's Sites
• AOL NetFind Kids Only
(http://www.aol.com/netfind/kids/)
• Blue Web'n (http://www.kn.pacbell.com/wired/bluewebn/)
• Education World (http://www.education-world.com/)
• Kid Info (http://www.kidinfo.com/)
• Kids Domain (http://www.kidsdomain.com)
• KidsClick! (http://sunsite.berkeley.edu/KidsClick!/)
• Yahooligans! (http://www.yahooligans.com)
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Subject Directories
• Hierarchically organized indexes of subject
categories
• User can browse through lists of Websites
by subject in search of relevant information
• Maintained by human
• May include a search engine for searching
their own database
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Examples of Subject Directories
• INFOMINE (Academic Scholarly Subject
Directory - http://infomine.ucr.edu/)
• LookSmart
• Lycos
• Magellan
(http://www.magellan.excite.com/)
• Open Directory (http://www.dmoz.org/)
• Yahoo
Many of these have aspects of both search and directory
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Specialized Subject Directory
• Guide complied by subject specialist
• List important resources in his/her area of
expertise
• More comprehensive than general guide
• Examples
– Film: Internet Movie Database (http://www.imdb.com/)
• Includes Clearinghouses
– Argus Clearinghouse (http://clearinghouse.net/)
– About.com
– WWW.Virtual Library (http://www.vlib.org/)
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Summary
• Search Engines
• The Big Guys
– Altavista
– Google
– Yahoo
• Meta-Search Tools
– Dogpile
– MetaCrawler
• Subject-Specific
– The BigHub.com
– Search Engine Colossus
• Subject Directory
– LookSmart
– Lycos
• Specialized Subject
Directory
– WWW.Virtual Library
– About.com
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Preparing to Search
• What’s the topic, question, area of interest?
• Identify search terms to describe your topic
of interest
• Consider synonyms (echinoderm OR
echinoidea OR "sea urchin")
• Consider variations of terms (restaurants,
dining, gourmet)
See Handout: Practical Steps
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Search tips
• Enclosing a multiword phrase in quotation
marks tells the search engine to list only
sites that contain that exact phrase
– Example: “heart disease”
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Boolean Logic
• Combines search terms in many databases
• AND, OR, and NOT or (+) and (-)
• Must check to see if search engines use
Boolean logic
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Boolean Logic : AND
Limits your search
“Oral History”
&
Women
Only returns pages with both of
these terms on them
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Boolean Logic : OR
Broadens your search
“Oral
History”
OR
Women
Returns every page with either of
these terms on them
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Boolean Logic : NOT
Limits your search
“Oral
History”
NOT
Women
Only returns pages that contain
one but not the other term on them
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Wildcards
• Special Character that can be appended to
the root of a word so you can search for all
possible endings to that root
• Good for variant spellings and common root
words
• Example
– rocket* will yield rocket, rockets, rocketry
psycholog* = psychology, psychological,
psychologist
– colo*r = color and colour
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Ctrl-F
• Follow a link to a document retrieved by a
search engine and don’t know how relevant
• Ctrl-F finds the relevant words in current
document
• Example: women +“El Salavdor” +“Oral
History”
– Pick one link, then Ctrl-F
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Searching Summary
• Choose a search engine
– Personal preference
– Different engines for different purposes
• Syntax - quotations, Boolean logic,
wildcards
• Ctrl-F to find search words
• Try to stay focused on your task
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