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The Internet and the Web

Irfan A. IlyasWeek13 – Lecture02-b

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Points to coverPoints to cover

Internet EmailInternet Email One-to-OneOne-to-One

Offline (Ordinary Email)Offline (Ordinary Email) Online (Instant Emailing- Chat)Online (Instant Emailing- Chat)

Group MailingGroup Mailing Mailing ListMailing List News GroupsNews Groups Chat GroupsChat Groups

Discussion Discussion Group TerminologyGroup Terminology Spam MailSpam Mail

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Internet EmailInternet Email

Chat (Instant Emailing)Chat (Instant Emailing) Lets the Internet users Lets the Internet users communicate interactivelycommunicate interactively Requires a Requires a three computer setupthree computer setup

Chat ServerChat Server Two Chat ClientsTwo Chat Clients

Buddy List User1User2User3

User1

User2

Chat Server

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Chat Mechanism DetailsChat Mechanism Details Server ComputerServer Computer

Chat server saves Chat server saves a list of registered users name.a list of registered users name. Lets Lets client computers login into the serverclient computers login into the server.. Marks the name of the clientsMarks the name of the clients (with a different color) who are (with a different color) who are

currently logged-incurrently logged-in Sends a selected list of client namesSends a selected list of client names to every logged-in client to every logged-in client

Client ComputerClient Computer User on a client computer uses a User on a client computer uses a chat client softwarechat client software

To get registered on the chat serverTo get registered on the chat server To login to the serverTo login to the server

User can User can select the user namesselect the user names for their buddys (friends) for their buddys (friends) Chat client will be Chat client will be receiving a list of these selected usersreceiving a list of these selected users

(with their current status) whenever logged in.(with their current status) whenever logged in.

A logged in chat user can initiate an instant email (chat) session with any A logged in chat user can initiate an instant email (chat) session with any other logged in user through the chat server.other logged in user through the chat server.

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Group EmailingGroup Emailing

Mail ListsMail Lists A A group of people (email addresses) are attachedgroup of people (email addresses) are attached to a to a

single group address (list address)single group address (list address) Any messageAny message sent to the list address will be sent to the list address will be copiedcopied

and automatically sentand automatically sent to all members to all members List ManagementList Management

Mail list management software are responsible forMail list management software are responsible for List address creationList address creation Linking usersLinking users to a list address (subscribing) to a list address (subscribing) Removing usersRemoving users from a list address (unsubscribing) from a list address (unsubscribing)

Mostly, such a Mostly, such a software is working eithersoftware is working either Through a Through a web page linkweb page link (for subscribe/ unsubscribe) OR (for subscribe/ unsubscribe) OR Sending emails to an automated managerSending emails to an automated manager (with the subject (with the subject

subscribe or unsubscribe)subscribe or unsubscribe)

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……Mail ListsMail Lists

How to subscribe/ How to subscribe/ unsubscribe a mailing unsubscribe a mailing list?list? Through a web pageThrough a web page

By sending By sending “subscription request” “subscription request” emailemail

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……Mail ListsMail Lists

Mail Mail List Archive SearchingList Archive Searching Using a Mailing List without initiating a new Using a Mailing List without initiating a new

discussiondiscussion Mailing List archive searching Mailing List archive searching allows members/ non-allows members/ non-

members to searchmembers to search for their interested topic for their interested topic (discussed in the past)(discussed in the past)

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Popular Mailing List AddressesPopular Mailing List Addresses

Description Subscription Address

Music andbands

dbird@netinfo.com.au

Movies moviereview-request@cuenet.com

Jokes dailyjoke@lists.ivillage.com

Travel tourbus@listserv.aol.com

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Group MailingGroup Mailing

News GroupsNews Groups Another mechanismAnother mechanism of having a group email of having a group email

discussiondiscussion

A A newsgroup server computernewsgroup server computer acts like an electronic acts like an electronic bulletin board spacebulletin board space

A A number of topicsnumber of topics for discussion are available (new for discussion are available (new ones can also be initiated)ones can also be initiated)

A separate network of newsgroup server computers is A separate network of newsgroup server computers is managing a managing a huge newsgroup setuphuge newsgroup setup, called , called USENETUSENET..

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.. News Groups.. News Groups

Details of USENETDetails of USENET USENET exists even before InternetUSENET exists even before Internet (started in (started in 19791979

by by Duke University & University of N. CarolinaDuke University & University of N. Carolina Graduates)Graduates)

Over Over 10,000 different newsgroups10,000 different newsgroups organized into organized into major topic areas (further subdivided into subtopics)major topic areas (further subdivided into subtopics)

MechanismMechanism All computersAll computers (news group servers) (news group servers) offer a bunch of newsoffer a bunch of news

groups for discussiongroups for discussion Whenever a message is posted to one of these computers, it Whenever a message is posted to one of these computers, it

will will eventually be copied (automatically) to all USENET eventually be copied (automatically) to all USENET computers.computers.

Comp windows …. News ….rec arts movies …..sci

talk

socrec.arts.movies

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……NewsgroupsNewsgroups

How to How to connect a newsgroupconnect a newsgroup computer? computer? Some of the USENET newsgroups are also Some of the USENET newsgroups are also

have a connection with the Internethave a connection with the Internet These computers can be contacted by These computers can be contacted by

Internet users through their Internet Address.Internet users through their Internet Address. The user The user needs a newsgroup reader programneeds a newsgroup reader program

(Microsoft Outlook Express can be used)(Microsoft Outlook Express can be used)Tower box

Tower box

Tower box

Tower box

Tower box

IBM Compatible

Workstation

IBM Compatible

Workstation

New York

Log Angeles

Washington

North Carolina

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……NewsgroupsNewsgroups

Newsgroup Servers at KFUPMNewsgroup Servers at KFUPM Two different newsgroup serversTwo different newsgroup servers are working are working

internally (not for public Internet)internally (not for public Internet) KFUPM Information TechKFUPM Information Tech. Center (ITC) is maintaining a . Center (ITC) is maintaining a

newsgroup server (newsgroup server (news.itc.kfupm.edu.sanews.itc.kfupm.edu.sa) for KFUPM ) for KFUPM Communities (student, faculty, staff). For details, visit Communities (student, faculty, staff). For details, visit http://www.kfupm.edu.sa/itc/newsgroup.htmlhttp://www.kfupm.edu.sa/itc/newsgroup.html

College of Computer Sci. & EngineeringCollege of Computer Sci. & Engineering (CCSE) newsgroup server (CCSE) newsgroup server ((nnews.ccse.kfupm.edu.saews.ccse.kfupm.edu.sa). For details, visit ). For details, visit http://www.ccse.kfupm.edu.sa/ccse/ccsenw/UNIX/News_grohttp://www.ccse.kfupm.edu.sa/ccse/ccsenw/UNIX/News_groups/news_groups.html ups/news_groups.html

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.. Newsgroup Servers at KFUPM.. Newsgroup Servers at KFUPM

Steps in setting up a Steps in setting up a newsgroupnewsgroup client client (Microsoft Outlook (Microsoft Outlook Express)Express) Create a news account Create a news account

((Tools/ Accounts/ New/ NewsTools/ Accounts/ New/ News ) )

Subscribe to the Subscribe to the newsgroups needednewsgroups needed

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.. Newsgroup Servers at KFUPM.. Newsgroup Servers at KFUPM

Download Download newsgroup newsgroup message listmessage list

Start Start reading messagesreading messages

Press Press SynchronizeSynchronize in order in order to make the bring the to make the bring the recent messagesrecent messages

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Discussion Group TermsDiscussion Group TermsTerm Description

Flaming Insulting, pulldown, attacking

Lurking Read with noparticipation

RFD Request fordiscussion

Saint Aids usersThread A sequence of

ongoing messagesWizard Comprehensive

knowledge

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Group MailingGroup Mailing

Group ChatsGroup Chats Allow multiple users to do interactive discussionsAllow multiple users to do interactive discussions Many discussion topics are availableMany discussion topics are available Topics exist on ad-hoc basis (come & go)Topics exist on ad-hoc basis (come & go) A popular group chart service for Internet users, is A popular group chart service for Internet users, is

IRC (Internet Relay Chat)IRC (Internet Relay Chat) Users need to have Users need to have an address of an IRC server computeran address of an IRC server computer IRC Client softwareIRC Client software is available for free is available for free Very similar to a one-to-one chat in terms of usage (Very similar to a one-to-one chat in terms of usage (results in results in

chat conferenceschat conferences))

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Spam MailSpam Mail

Unwanted mail/ Junk mailUnwanted mail/ Junk mail Being used by marketing departments Being used by marketing departments

sending advertisements etc. to as many as sending advertisements etc. to as many as possiblepossible

‘‘address thieves’ are selling addresses to address thieves’ are selling addresses to such companies.such companies.

Legislation has been approved for Legislation has been approved for penalties etc.penalties etc.

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Points to coverPoints to cover

Introducing Web Search Engines Introducing Web Search Engines Web Search Index (directories)Web Search Index (directories) Web Search Engines Web Search Engines Web Meta Search EnginesWeb Meta Search Engines

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Introducing Web Search ToolsIntroducing Web Search Tools

Early 80’s Web was manageable with Early 80’s Web was manageable with simple simple SurfingSurfing (exploring web sites through hyperlink (exploring web sites through hyperlink clicks)clicks)

Information explosion on the Web Information explosion on the Web makes Surfing makes Surfing nearly a “time wastage activity”nearly a “time wastage activity”

Web Search ToolsWeb Search Tools are meant for overcoming the are meant for overcoming the challenge of “challenge of “finding relevant informationfinding relevant information” on ” on today’s huge Webtoday’s huge Web

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… … Introducing Web Search ToolsIntroducing Web Search Tools

Types of Types of Search Tools available Search Tools available on the Neton the Net Web Web Search IndexSearch Index (Starting Point Page) (Starting Point Page) Web Web Search EnginesSearch Engines Web Web Meta Search EnginesMeta Search Engines

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1. Web Search Index1. Web Search Index

A web search index is A web search index is a collection of a large a collection of a large number number of useful web site addressesof useful web site addresses

The address collection is presented in an The address collection is presented in an organized fashionorganized fashion A A subject treesubject tree is maintained is maintained Sub-topics are maintainedSub-topics are maintained under each subject under each subject Collection of web Collection of web addresses are provided at the addresses are provided at the

lowest levellowest level of this tree. of this tree.

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……A Web Search through Yahoo Web IndexA Web Search through Yahoo Web Index

List of Web Addresses UnderComputers and Internet > Magazines > ECommerce

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… … Web Search IndexWeb Search Index

Helps the user Helps the user to find general informationto find general information on a on a subject area.subject area. Examples:Examples:

Finding links for popular computer magazinesFinding links for popular computer magazines Finding pages discussing food recipes Finding pages discussing food recipes

Main problemsMain problems with Web Search Index with Web Search Index Very Very small fraction of web addressessmall fraction of web addresses can be covered can be covered

(limited scope)(limited scope) Needs an Needs an exhaustive effort to keep the index up-to-exhaustive effort to keep the index up-to-

datedate (web explosion rate is exponential) (web explosion rate is exponential) Not very good for finding specific Not very good for finding specific informationinformation

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……Details of Yahoo Search IndexDetails of Yahoo Search Index

Index AdministrationIndex Administration Works upon a Works upon a distributive modeldistributive model Allows all Allows all Internet users to suggest different sitesInternet users to suggest different sites for for

inclusion into Yahoo! site Indexinclusion into Yahoo! site Index In order to create a fair and intuitive Index that is of In order to create a fair and intuitive Index that is of

use to everyone use to everyone Yahoo!'s subject editorsYahoo!'s subject editors (people qualified in subject (people qualified in subject

categorization/ identification) will review the sitecategorization/ identification) will review the site The The site may or may not be acceptedsite may or may not be accepted depending upon its depending upon its

usabilityusability If the site is acceptableIf the site is acceptable, a specific sub-category, a specific sub-category is assigned is assigned

to the site to the site The site address is then included into the index treeThe site address is then included into the index tree

Yahoo Express Program Yahoo Express Program

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……Web Search IndexWeb Search Index

How to choose a How to choose a good Search Index?good Search Index? Understanding LimitationsUnderstanding Limitations

How many sites?How many sites? What type of sites (http, gopher, usenet etc.) can be What type of sites (http, gopher, usenet etc.) can be

accessed?accessed?

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2. Web Search Engines2. Web Search Engines Search Engines evolved in order Search Engines evolved in order to overcome the challenge of Search Index to overcome the challenge of Search Index

administrationadministration

A A search engine uses a huge database of web addressessearch engine uses a huge database of web addresses, n, not-categorizedot-categorized to any subjectto any subject

Search engine is Search engine is using a special automated programusing a special automated program, called , called spiderspider (wanderers or worms)(wanderers or worms)

A A Spider is capable ofSpider is capable of: : Automatically Automatically discovering web sitediscovering web site addresses addresses Visits these addresses silently and Visits these addresses silently and reading HTML documentsreading HTML documents updating the databaseupdating the database with new (emerging) web document URL with details of with new (emerging) web document URL with details of

there contents (word counts for different words)there contents (word counts for different words)

A search engine allows the user:A search engine allows the user: to to search for specific words (key words)search for specific words (key words) relevant to their interested topics on all relevant to their interested topics on all

the saved web URLsthe saved web URLs

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… … 2. Web Search Engines2. Web Search Engines

Search engine programs are normally Search engine programs are normally accessible through Web accessible through Web addressesaddresses

Most search engines Most search engines also provide a search index listalso provide a search index list of web of web addressesaddresses

ExamplesExamples: : Yahoo Search EngineYahoo Search Engine (http://www.yahoo.com) (http://www.yahoo.com) Lycos Search EngineLycos Search Engine (http://www.lycos.com) (http://www.lycos.com)

Drawbacks of Search EnginesDrawbacks of Search Engines Poor precisionPoor precision of the searched document list of the searched document list Poor searching approach Poor searching approach Varied document qualityVaried document quality Server overloadServer overload Use of Use of complex keyword formulas complex keyword formulas

making use of AND/ OR/ NOT operators for making a detailed making use of AND/ OR/ NOT operators for making a detailed searchsearch

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Comparing Popular Search EnginesComparing Popular Search Engines

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Adding your site to a Search EngineAdding your site to a Search Engine

How to How to include your siteinclude your site into a search into a search engine database?engine database? NoNo need of need of manual inclusionmanual inclusion Automated spider programsAutomated spider programs will visit emerging will visit emerging

sites and include their URLs into their sites and include their URLs into their databasedatabase

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3. Meta Search Engines3. Meta Search Engines Special search engine service which utilizes multiple search engine Special search engine service which utilizes multiple search engine

databasesdatabases

A meta searcher doesn’t have its own URL database. A meta searcher doesn’t have its own URL database.

Takes user search request and submit it to multiple search engines Takes user search request and submit it to multiple search engines for searchingfor searching

Needs some work in compiling the retrieved URL list Needs some work in compiling the retrieved URL list Remove duplicate searchesRemove duplicate searches Sort the list according to the document relevanceSort the list according to the document relevance integrate results well, integrate results well, eliminate duplicates, eliminate duplicates, offer additional features such as intelligent ranking or clustering by offer additional features such as intelligent ranking or clustering by

subjects within the search results subjects within the search results

More Info About Meta Search Engines: More Info About Meta Search Engines:

http://www.lib.berkeley.edu/TeachingLib/Guides/Internet/MetaSearch.htmlhttp://www.lib.berkeley.edu/TeachingLib/Guides/Internet/MetaSearch.html

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Search List from a Meta Search EnginesSearch List from a Meta Search Engines

Name of the Search Engine

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Example Meta Searcher SitesExample Meta Searcher Sites

Meta CrawlerMeta Crawler

CNet’s CNet’s Search.comSearch.com

Highway 16Highway 16

A collection of A collection of many meta many meta searcherssearchers

http://www.infospace.com/info.metac/http://www.infospace.com/info.metac/about/corporate/about.htmabout/corporate/about.htm

http://www.search.com/http://www.search.com/

http://www.highway61.com/http://www.highway61.com/

http://searchenginewatch.com/http://searchenginewatch.com/links/metacrawlers.htmllinks/metacrawlers.html

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