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Introduction to Information and Computer Science
Internet and the World Wide Web
Lecture b
This material (Comp4_Unit2b) was developed by Oregon Health and Science University, funded by the Department of Health and Human Services, Office of the National Coordinator for Health Information Technology under Award Number
IU24OC000015
Internet and the World Wide WebLearning Objectives
• Define the Internet and how to connect to it (Lecture a and b)
• Define the World Wide Web and how to access it (Lecture a and b)
• Write effective search queries for Internet search engines, filter the results and evaluate credibility of information (Lecture b)
• Discuss security and privacy concerns on the Internet (Lecture c)
• Describe ethical issues for the Internet (Lecture c and d)• Explore online healthcare applications and associated
security and privacy issues including HIPAA (Lecture d)
2Health IT Workforce Curriculum Version 3.0/Spring 2012
Introduction to Information and Computer Science Internet and the World Wide Web
Lecture b
Service Providers and You
• Internet Access Providers connect users to the Internet. Commonly known as ISPs Access to the Internet revolves around the use of
ISPs ISPs are organized as local, regional, and national
providers Local providers connect to a regional provider
Might only work in a limited number of cities
3Health IT Workforce Curriculum Version 3.0/Spring 2012
Introduction to Information and Computer Science Internet and the World Wide Web
Lecture b
Service Providers and You (continued)
• Regional providers connect to national providers Usually operate in parts of a number of states or
provinces• National providers provide high-speed data
transfer with each other to provide a robust, redundant system Provides connectivity to every other network on the
Internet without needing to pay for it
4Health IT Workforce Curriculum Version 3.0/Spring 2012
Introduction to Information and Computer Science Internet and the World Wide Web
Lecture b
Internet Access for a Fee• Since ISPs must maintain equipment and pay
salaries, they provide access for a fee• Fees based on type of service available and
desired speed Dial-up is available everywhere in the U.S. But is it
very slow! Cost is approx. $10/month DSL is much faster than dial-up but is not available in
many locations. Cost is approx. $50/month Cable is usually much faster than DSL but is only
available where cable companies have installed coaxial cable in streets. Cost is approx. $60/month
5Health IT Workforce Curriculum Version 3.0/Spring 2012
Introduction to Information and Computer Science Internet and the World Wide Web
Lecture b
Provider Equipment• ISPs usually provide the equipment required to
connect to their service for purchase or for a monthly lease fee (known as provider equipment) Dial-up connections require a modem on the premises.
A computer connects to the modem and the modem connects to the ISP’s wall connection, which provides Internet access.
DSL connections require a DSL modem and connect similar to dial-up
Cable connections require a cable modem router and connect similar to dial-up.
6Health IT Workforce Curriculum Version 3.0/Spring 2012
Introduction to Information and Computer Science Internet and the World Wide Web
Lecture b
Customer Premises Equipment
• Private networks usually have their own equipment Private (home or business) network usually consists
of computers, laptops, WAPs, and switches All private devices can connect to a switch, which
then connects to the ISP’s equipment via a network cable
With this setup, all private devices can access the Internet and share the same Internet connection
7Health IT Workforce Curriculum Version 3.0/Spring 2012
Introduction to Information and Computer Science Internet and the World Wide Web
Lecture b
Leasing an IP Address
• ISPs lease IP addresses to subscribers. Private (home or business) network usually utilizes
private IP addresses The ISP typically leases a location one public IP
address The ISP’s equipment is provided with a public IP
address to connect to the ISP’s public network The ISP’s equipment is also provided with a private
IP address to connect to a private network
8Health IT Workforce Curriculum Version 3.0/Spring 2012
Introduction to Information and Computer Science Internet and the World Wide Web
Lecture b
Leasing a Dynamic IP Address
• The ISP’s equipment is able to translate addressing between the private and public networks
• ISPs generally provide an IP address that may change from day to day This is a typical leased, dynamic IP address and is
included in the monthly fee
9Health IT Workforce Curriculum Version 3.0/Spring 2012
Introduction to Information and Computer Science Internet and the World Wide Web
Lecture b
Leasing a Static IP Address
• ISPs can also lease an IP address for the duration of the contract The static IP address will not change
• Most Web sites use static IP addresses so that their domain name will be reliably mapped to one IP address
• ISPs charge more each month for static IP address. The charge ranges from $5 to $100, depending on provider.
10Health IT Workforce Curriculum Version 3.0/Spring 2012
Introduction to Information and Computer Science Internet and the World Wide Web
Lecture b
DNS - Another ISP Service
• ISPs provide a first-level of DNS servers ISP DNS servers connect to global DNS root servers
for help when they cannot resolve a name to an IP address
Using an ISP’s DNS servers makes for a speedier browsing experience!
11Health IT Workforce Curriculum Version 3.0/Spring 2012
Introduction to Information and Computer Science Internet and the World Wide Web
Lecture b
Searching the Internet
• Search engines search Web pages for information using an algorithm Information includes keywords and other information
found on Web pages Not a Web directory, which is a site that manually lists
sites by category, etc The Web site Craigslist offers a Web directory and
search engine on its site
12Health IT Workforce Curriculum Version 3.0/Spring 2012
Introduction to Information and Computer Science Internet and the World Wide Web
Lecture b
Search Engine Providers• Google – http://www.google.com • Bing™ (Microsoft) - http://www.bing.com/ • Yahoo! - http://www.yahoo.com/ • Ask® - http://www.ask.com/ • Others?
13Health IT Workforce Curriculum Version 3.0/Spring 2012
Introduction to Information and Computer Science Internet and the World Wide Web
Lecture b
How Do Search Engines Function?• Search engines gather data• Web crawler programs are programmed with
proprietary algorithms to gather HTML coding on Web pages• An algorithm is a set of instructions set out logically to
solve a problem or reach a desired goal• Search providers own proprietary algorithms that
provide distinct search results Some algorithms are better than others
14Health IT Workforce Curriculum Version 3.0/Spring 2012
Introduction to Information and Computer Science Internet and the World Wide Web
Lecture b
How Do Search Engines Function? (continued)
• Gathered data is analyzed and indexed and used to provide search results Indexed data is stored in a database, owned by the
search provider• Search engine software searches its indexed
data based on search criteria
15Health IT Workforce Curriculum Version 3.0/Spring 2012
Introduction to Information and Computer Science Internet and the World Wide Web
Lecture b
Using a Search Engine• Search using a phrase (also known as a query)
Engine analyzes its indices, looking for pages that most closely match
• Type “what is the internet” (without quotes) in a search line Try it now and select the Wikipedia entry near the top
of the page
16Health IT Workforce Curriculum Version 3.0/Spring 2012
Introduction to Information and Computer Science Internet and the World Wide Web
Lecture b
Using a Search Engine (continued)
• Use wildcards in your search phraseSearching for “search engine list 20*” (without
quotes) returns sites listing search engine rankings for the year 2000 through 2099
Try it now!
17Health IT Workforce Curriculum Version 3.0/Spring 2012
Introduction to Information and Computer Science Internet and the World Wide Web
Lecture b
Using a Search Engine (continued)• Use Boolean operators AND, OR, and NOT to
restrict or augment the search phrase. AND – searching for “cardiac and arrest” (without
quotes) will list Web pages containing both words (not one word or the other)
OR – Searching for “cardiac or arrest” (without quotes) will list Web pages containing either word or both words
NOT – Searching for “cardiac and arrest not flu” (without quotes) will list Web pages containing “cardiac” and “arrest” but not the word “flu”
18Health IT Workforce Curriculum Version 3.0/Spring 2012
Introduction to Information and Computer Science Internet and the World Wide Web
Lecture b
Web Search TipsWeb searching is not case-sensitiveBe specific. Don’t search for “car” (a generic
noun) when you could be specific with a make, model, and year
Use short search phrases of 2-3 words when possible. Less is more!
Searching with phrases in quotes restricts the search results
19Health IT Workforce Curriculum Version 3.0/Spring 2012
Introduction to Information and Computer Science Internet and the World Wide Web
Lecture b
Web Search Tips (continued)
• Using Quotes MattersSearching for “Phantom of the Opera” (with
quotes) will return Web pages that contain that phrase, in that word order
Searching for Phantom of the Opera (without quotes) will return Web pages that contain the words “phantom” and/or “opera” in no particular order
20Health IT Workforce Curriculum Version 3.0/Spring 2012
Introduction to Information and Computer Science Internet and the World Wide Web
Lecture b
Search Results in a Nutshell• When a Web site appears at the top of a results
list Keywords found on Web site by Crawler match
search phrase Popular Web sites (those visited often) match search
phrase Paying sites may appear on the top or side of the
page, near the unpaid-for search results
21Health IT Workforce Curriculum Version 3.0/Spring 2012
Introduction to Information and Computer Science Internet and the World Wide Web
Lecture b
Internet and World Wide WebSummary – Lecture b
• Devices connect to the Internet through an interconnected network of ISPs
• ISP fees include the use of their equipment, which is used to connect a network to the Internet
• ISPs provide IP addresses and DNS services to their subscribers
• People search for content on Web pages through the use of search engines, which are provided by a number of different companies
22Health IT Workforce Curriculum Version 3.0/Spring 2012
Introduction to Information and Computer Science Internet and the World Wide Web
Lecture b
Internet and World Wide WebSummary – Lecture b (continued)
• Search terms can include Boolean operators, which can augment or limit search engine results
• Search terms can be enclosed in double quotes, which limits search engine results
• Search engine results are influenced by search terms and payments to search providers by vendors
23Health IT Workforce Curriculum Version 3.0/Spring 2012
Introduction to Information and Computer Science Internet and the World Wide Web
Lecture b
Internet and the World Wide WebReferences – Lecture b
References• Parsons JJ, Oja D. Chapter 1: Computers and Digital Basics. In: New Perspectives on Computer Concepts 2011:
Comprehensive. 13th ed. Boston: Course Technology; 2010.• Shelley GB, Vermaat ME. Chapter 1: Introduction to Computers. In: Discovering Computers 2011: Introductory.
1st ed. Boston: Course Technology; 2010.• Web search engine. Wikipedia [free encyclopedia on the Internet]. 2010 July 11; [cited 12 July 2010]; Available
from: http://en.wikipedia.org/wiki/Web_search_engine.. Accessed Jan 2012.• Internet Service Provider. Wikipedia [free encyclopedia on the Internet]. 2010 July 12; [cited 12 July 2010];
Available from: http://en.wikipedia.org/wiki/Internet_service_provider.. Accessed Jan 2012. • Search the Web. Ask.com [search engine on the Internet]. 2010 July 12; [cited 12 July 2010]; Available from:
http://www.ask.com. Accessed Jan 2012.• Bing. Bing.com [search engine on the Internet]. 2010 July 12; [cited 12 July 2010]; Available from:
http://www.bing.com. Accessed Jan 2012.• Google. Google.com [search engine on the Internet]. 2010 July 12; [cited 12 July 2010]; Available from:
http://www.google.com. Accessed Jan 2012.• Yahoo!. Yahoo!.com [search engine on the Internet]. 2010 July 12; [cited 12 July 2010]; Available from:
http://www.yahoo.com. Accessed Jan 2012.
24Health IT Workforce Curriculum Version 3.0/Spring 2012
Introduction to Information and Computer Science Internet and the World Wide Web
Lecture b