Email & Web Email & Web SearchesSearches

Kin 260Kin 260

Jackie KiwataJackie Kiwata

OverviewOverview

EmailEmail– Message Transfer AgentsMessage Transfer Agents– User AgentsUser Agents– Envelope & ContentsEnvelope & Contents

Web SearchesWeb Searches– Search EnginesSearch Engines– Key WordsKey Words– OperatorsOperators– CSLA Library ResearchCSLA Library Research

Electronic MailElectronic Mail

Use of email by general public exploded Use of email by general public exploded in the 1990sin the 1990s

Prior to 90’s, used mostly in academiaPrior to 90’s, used mostly in academia Email systems composed of 2 Email systems composed of 2

subsystemssubsystems– User AgentsUser Agents– Message Transfer AgentsMessage Transfer Agents

Key idea behind email system: Key idea behind email system: envelope and contentsenvelope and contents– Separate routing information from messageSeparate routing information from message

Message Transfer AgentsMessage Transfer Agents

Move messages from source to Move messages from source to destinationdestination

Use Use daemonsdaemons– Computer Science definition: processes Computer Science definition: processes

that run in the backgroundthat run in the background– NOT:NOT:

DaemonsDaemons

Purpose:Purpose:– Establish connection to destinationEstablish connection to destination– Reliably transfer messageReliably transfer message– Close connectionClose connection– Perform steps automatically without Perform steps automatically without

bothering userbothering user

Daemon ExampleDaemon Examplefromfrom <mailer-daemon@googlemail.com><mailer-daemon@googlemail.com>toto jkiwata2@csla.edu,jkiwata2@csla.edu,datedate Nov 8, 2007 1:42 PMNov 8, 2007 1:42 PMSubject: Delivery Status Notification (Failure)Subject: Delivery Status Notification (Failure)

This is an automatically generated Delivery Status This is an automatically generated Delivery Status NotificationNotification

Delivery to the following recipient failed permanently:Delivery to the following recipient failed permanently:

ladyleedoc@yahoo.comladyleedoc@yahoo.com

Technical details of permanent failure:Technical details of permanent failure:PERM_FAILURE: SMTP Error (state 13): 550 PERM_FAILURE: SMTP Error (state 13): 550

<ladyleedoc@yahoo.com> recipient rejected<ladyleedoc@yahoo.com> recipient rejected

User AgentsUser Agents

Normally a programNormally a program Accepts a variety of commands, Accepts a variety of commands,

including:including:– Composing messagesComposing messages– Receiving messagesReceiving messages– Replying to messagesReplying to messages– Manipulating mailboxesManipulating mailboxes

e.g. Outlook, Gmail, Hotmaile.g. Outlook, Gmail, Hotmail

Email - EnvelopeEmail - Envelope

Read by Message Transfer Agents Read by Message Transfer Agents – Not seen by person reading emailNot seen by person reading email

Encapsulates the messageEncapsulates the message Similar to paper envelopes transported by Similar to paper envelopes transported by

the post officethe post office Contains all the information needed to Contains all the information needed to

transport the messagetransport the message– Destination AddressDestination Address– PriorityPriority– Security LevelSecurity Level

Email - ContentEmail - Content

Content consists of two partsContent consists of two parts

1.1. HeaderHeader- contains information for User Agentscontains information for User Agents

2.2. BodyBody- Contains the message read by the - Contains the message read by the

human recipienthuman recipient

Anatomy of an Email Anatomy of an Email messagemessage

Return-Path: <example-return-9792-Return-Path: <example-return-9792-ccsxxx=bath.ac@gmail.com>ccsxxx=bath.ac@gmail.com>

Received: from roche.bath.ucla.edu ([138.38.32.21] Received: from roche.bath.ucla.edu ([138.38.32.21] ident=yalrla9a1j69szla2ydr) by ident=yalrla9a1j69szla2ydr) by serena.bath.smtp.gmail with esmtp; Sat, 07 Jun serena.bath.smtp.gmail with esmtp; Sat, 07 Jun 2007 20:17:35 +01002007 20:17:35 +0100

Date: Sat, 7 Jun 2001 12:35:58 -0700Date: Sat, 7 Jun 2001 12:35:58 -0700From: Jane Martin<jmartin@gmail.com>From: Jane Martin<jmartin@gmail.com>To: Bob Richards <brichards@ucla.edu>To: Bob Richards <brichards@ucla.edu>Subject: Athletic Director PositionSubject: Athletic Director Position

Message-ID: Message-ID: <20030607123558.A2408@ring.CS.example.com<20030607123558.A2408@ring.CS.example.com>>

User-Agent: Mutt/1.2.5.1iUser-Agent: Mutt/1.2.5.1i

Dear Mr. Richards:Dear Mr. Richards:Please find my resume attached. Please find my resume attached. Sincerely,Sincerely,Jane MartinJane Martin

Header

Body

Transfer ProtocolsTransfer Protocols

How User Agents talk to Message How User Agents talk to Message Transfer AgentsTransfer Agents

Daemons will speak one of the Daemons will speak one of the following protocols:following protocols:– SMTP: Simple Mail Transfer ProtocolSMTP: Simple Mail Transfer Protocol– POP3: Post Office Protocol 3POP3: Post Office Protocol 3– IMAP: Internet Message Access ProtocolIMAP: Internet Message Access Protocol

e.g. Gmail uses POP3 to receive mail e.g. Gmail uses POP3 to receive mail and SMTP to send mailand SMTP to send mail

Web SearchesWeb Searches

Web is a terrific place to obtain info Web is a terrific place to obtain info on any topicon any topic

But all too often, waste time on But all too often, waste time on reviewing useless web site resultsreviewing useless web site results

There has to be a better way!There has to be a better way!

Making Searches BetterMaking Searches Better

1. 1. Use a sophisticated search engineUse a sophisticated search engine

i.e. Googlei.e. Google

2. 2. Choose key words wiselyChoose key words wisely

i.e. “Exercise Science programs” i.e. “Exercise Science programs” instead of “Exercise”instead of “Exercise”

3. 3. Refine search query with OperatorsRefine search query with Operators

i.e. +, -, “”i.e. +, -, “”

Web Search EnginesWeb Search Engines

Provide an interface to search for Provide an interface to search for pages, images or other types of pages, images or other types of web filesweb files

Use algorithms Use algorithms Work by:Work by:

1.1. Web crawlingWeb crawling

2.2. IndexingIndexing

3.3. SearchingSearching

Web CrawlingWeb Crawling

Accomplished using web crawlers, or Accomplished using web crawlers, or spidersspiders– Automated programs that browse pages Automated programs that browse pages

on the WWWon the WWW Crawlers create a copy of visited Crawlers create a copy of visited

pages for use in later analysispages for use in later analysis

IndexingIndexing

Contents of stored pages are Contents of stored pages are analyzedanalyzed– Words extracted from titles, headings, Words extracted from titles, headings,

and special fields called meta tagsand special fields called meta tags Data about web pages are stored in Data about web pages are stored in

an index databasean index database When a user enters a search query, When a user enters a search query,

search engine checks the index search engine checks the index databasedatabase

Searching & ResultsSearching & Results

Search engine returns results based Search engine returns results based on search queryon search query

Search engine will rank the results and Search engine will rank the results and show most relevant higher in the listshow most relevant higher in the list– Most relevant = how closely key words Most relevant = how closely key words

match on web pagematch on web page– Issue: In 2006, spammers created Issue: In 2006, spammers created

websites containing random sequences of websites containing random sequences of high-traffic keywords. Results were high-traffic keywords. Results were polluted with pages that contained little polluted with pages that contained little or no relevance.or no relevance.

Choosing Key WordsChoosing Key Words

Key to finding information quicklyKey to finding information quickly Get better results if use multiple Get better results if use multiple

search terms that are specificsearch terms that are specific E.g. “Sports” vs. “Sports medicine E.g. “Sports” vs. “Sports medicine

programs in California”programs in California” Note: Google will ignore Note: Google will ignore

capitalization and common words like capitalization and common words like “and”, “or”, “how”“and”, “or”, “how”

Basic OperatorsBasic Operators

1.1. Quotes “”Quotes “”- Will search for pages with exact phrase- Will search for pages with exact phrase- Good if know title of article- Good if know title of article- E.g. “Expression of the bilateral deficit”- E.g. “Expression of the bilateral deficit”

2.2. Positive Terms +Positive Terms +- If put + before a word, search engine If put + before a word, search engine

must return results that include the must return results that include the wordword

- Use if search is omitting common words Use if search is omitting common words essential to resultsessential to results

- E.g. Star Wars Episode +1E.g. Star Wars Episode +1

Basic Operators, con’t.Basic Operators, con’t.

3. 3. Negative Terms –Negative Terms –

- If put – before a word, search engine - If put – before a word, search engine will omit results containing wordwill omit results containing word

- Use if search term has more than one - Use if search term has more than one meaningmeaning

-e.g. vo2max test -cycle-e.g. vo2max test -cycle

-e.g. rehab -winehouse-e.g. rehab -winehouse

Advanced OperatorsAdvanced Operators

1.1. OR searchOR search- Find results that include either of 2 Find results that include either of 2

search termssearch terms- e.g. vo2max test cycle OR treadmille.g. vo2max test cycle OR treadmill

2.2. Domain searchDomain search- Find results on one specific websiteFind results on one specific website- E.g. biomechanics site:www.usc.eduE.g. biomechanics site:www.usc.edu

3.3. Fill in the blanks search *Fill in the blanks search *- Ask Google to fill in the blank for youAsk Google to fill in the blank for you- Add an * at the part you want filled inAdd an * at the part you want filled in-- e.g. glycolysis discovered by *e.g. glycolysis discovered by *

Helpful Specialized Search Helpful Specialized Search SitesSites

CSLA LibraryCSLA Library– http://www.calstatela.edu/library/http://www.calstatela.edu/library/

Google ScholarGoogle Scholar– http://scholar.google.comhttp://scholar.google.com– Searches research publications, booksSearches research publications, books

Google Image searchGoogle Image search– http://images.google.comhttp://images.google.com – Only returns results that contain imagesOnly returns results that contain images

Practical Ex. – CSLA Library Practical Ex. – CSLA Library SearchSearch

Usually, will use Article search

Then can choose database by Subject (i.e. Kinesiology)

Or choose database directly by name (i.e. Medline)

Helpful HintsHelpful Hints Can access CSLA library databases from homeCan access CSLA library databases from home

– Must have NIS accountMust have NIS account– If use ERIC, can only access abstracts, not full textIf use ERIC, can only access abstracts, not full text

Most efficient to least efficient searching Most efficient to least efficient searching terms:terms:

1.1. TitleTitle

2.2. KeywordKeyword

3.3. AuthorAuthor

4.4. AbstractAbstract

5.5. All textAll text

Ex – Medline SearchEx – Medline Search

You want to find studies on caffeine You want to find studies on caffeine supplementation during high-supplementation during high-intensity exercise bouts of varying intensity exercise bouts of varying duration on a cycle ergometer.duration on a cycle ergometer.

Use the MEDLINE database through Use the MEDLINE database through the CSULA librarythe CSULA library

Must find the full text version (html Must find the full text version (html or pdf).or pdf).

Extra CreditExtra Credit

In preparation for next lecture, do the In preparation for next lecture, do the following:following:

1.1. Sign up for gmail (free)Sign up for gmail (free)2.2. Email me from your gmail accountEmail me from your gmail account3.3. Do this by 5:00 pm on Friday and I Do this by 5:00 pm on Friday and I

will add 1 extra point to your overall will add 1 extra point to your overall lab scorelab score

If you already have a gmail If you already have a gmail account, just do steps 2-3. account, just do steps 2-3.

ReferencesReferences

Google Search GuideGoogle Search Guide

http://www.google.com/intl/en/help/basics.http://www.google.com/intl/en/help/basics.htmlhtml

Wiki Search Engine pageWiki Search Engine pagehttp://en.wikipedia.org/wiki/Web_search_enginehttp://en.wikipedia.org/wiki/Web_search_engine

EmailEmail

Tanenbaum, A. S. (2003). Tanenbaum, A. S. (2003). Computer Computer NetworksNetworks. Upper Saddle River, NJ: Prentice . Upper Saddle River, NJ: Prentice HallHall