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Ch 8Ch 8 22
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
Ch 8Ch 8 33
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
Ch 8Ch 8 44
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.
Ch 8Ch 8 55
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)
Ch 8Ch 8 66
……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
Ch 8Ch 8 77
……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)
Ch 8Ch 8 88
Popular Mailing List AddressesPopular Mailing List Addresses
Description Subscription Address
Music andbands
Movies [email protected]
Jokes [email protected]
Travel [email protected]
Ch 8Ch 8 99
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..
Ch 8Ch 8 1010
.. 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
Ch 8Ch 8 1111
……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
Ch 8Ch 8 1212
……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
Ch 8Ch 8 1313
.. 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
Ch 8Ch 8 1414
.. 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
Ch 8Ch 8 1515
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
Ch 8Ch 8 1616
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))
Ch 8Ch 8 1717
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.
Ch 8Ch 8 1818
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
Ch 8Ch 8 1919
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
Ch 8Ch 8 2020
… … 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
Ch 8Ch 8 2121
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.
Ch 8Ch 8 2222
……A Web Search through Yahoo Web IndexA Web Search through Yahoo Web Index
List of Web Addresses UnderComputers and Internet > Magazines > ECommerce
Ch 8Ch 8 2323
… … 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
Ch 8Ch 8 2424
……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
Ch 8Ch 8 2525
……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?
Ch 8Ch 8 2626
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
Ch 8Ch 8 2727
… … 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
Ch 8Ch 8 2929
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
Ch 8Ch 8 3030
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
Ch 8Ch 8 3131
Search List from a Meta Search EnginesSearch List from a Meta Search Engines
Name of the Search Engine
Ch 8Ch 8 3232
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