Learning
Objectives
The Need for
Computer Literacy
The Computer
Defined
The Computer:
Its Uses
The Five Elements
of the Computing Process
The Computer:
Its Advantages
Positive and
Negative Effects
Lesson Summary
Laboratory Exercises
Lesson
Review
Further Discovery
Online Discovery
Related Web Sites
QNotes
Learning Objectives When you have finished reading this lesson, you will be able to
Explain the need for computer
literacy in tomorrow's computer society
Explain what a computer is
and how it processes data to produce information
Discuss the characteristics
of computers that explain why they are so widely used
Distinguish the major types
of computers and their principal uses
Describe the major types
of general-purpose application programs and provide examples of their uses
Distinguish between data
and information
Explain how computers represent
data (bits and bytes)
Identify the main elements
of a typical computing process
Explain the relationship
between computer professionals and other computer users
Understand the computer's
positive and negative effects on society
Today, did you stop for a red signal
or buy something at a store? Did you watch a movie or a television program?
Did you drive a car or ride a bus? All these activities, and thousands
more, involve computers in some way. Computers of every size affect our
lives. Supercomputers forecast weather and launch satellites. Embedded
computer processor chips make "smart" devices such as a car that
warns you of problems, or a microwave oven that warms your breakfast.
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Computers put banking at your fingertips anytime and anywhere. Would you choose a bank that didn't have automated teller machines (ATMs)? In addition, you no longer need to carry cash or checks all the time; you can buy many things--from groceries to gasoline to hamburgers--by using a debit card.
The newest university in the California State College and University system, at Monterey, has a bookless library. How do you do research? You use a computer.
Information from all over the world is available to anyone with a computer, a modem, a telephone line, and an Internet account. Students from kindergarten to graduate school are using computers to gather data. Networks and telecommunications give "looking it up" a new meaning.
Even political boundaries are challenged by computers. When you are "talking" on a network such as the Internet, you can communicate with people from around the world.
A revolution changes the way we do things and think about things, and
computers have created a revolution. We have become dependent on computers--we
expect them to be there for us. Computers are shaking up our world.
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| Computer are part of our daily lives at home, at work, and at school. | |||
The Need for Computer Literacy A major technological revolution has both positive and negative effects. Because the computer revolution is so new, many effects are still to be discovered. But there's one effect you can count on--the effect on you and your future. Because computers have moved into society so rapidly and so completely, you need basic computer skills just to pursue your career goals and function effectively in society. In short, you need computer literacy, sufficient computer knowledge to prepare you for working and living in a computerized society.
For many people, computer literacy means simply knowing which key to press. That knowledge is important, but it isn't enough. You need to understand some fundamental concepts about how computer systems are set up and how they work. To see this point, think about cars. Assume that you have learned to drive and you can get from point A to point B. If you want to maintain your car and drive with maximum safety, however, you must learn more. For example, does your car have an antilock braking system (ABS)? If so, in a sudden stop, the brake pedal normally vibrates. But some people do not know this fact. They think that something is wrong, and they release the brake pedal--resulting in crashes that could have been prevented. In the same way, lack of knowledge causes people to make mistakes using computers.
Lack of knowledge also causes some people to fear computers. We have even coined a term to describe this irrational fear: cyberphobia.
The purpose of this book is to teach you the fundamental concepts of computers and their uses. With this knowledge, you will be able to learn more rapidly how to use computers effectively--tomorrow's computers as well as today's. You will quickly recognize tasks that can benefit from computer applications. You will know how to make wise choices when you select computer equipment. You will know how to gauge the gravity of the computer's potentially negative effects, such as its threat to jobs and individual privacy. And most of all, you will be prepared for full citizenship in a society that requires computer literacy for the best jobs and careers.
This lesson introduces fundamental computer concepts. You learn what
a computer is, what it does, and--to some extent--how it works.
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| Computers influence many of the activities in a typical day--from watching television to shopping to recreation. |
The Computer Defined To many people, the word computer suggests "computation," and that word means "math," which scares some people. But this connection is misleading. Computers are not calculators, although you can turn a computer into a calculator. In the simplest definition, a computer is an electronic device--a flexible machine that can manipulate data. Many of these manipulations have nothing to do with math. In addition to being used for such tasks as adding up your supermarket bill or getting $20 bills at an ATM, computers are used by writers, television producers, musicians, poets, graphics illustrators, and scholars of medieval history!
Why are computers so flexible that physicists and poets feel equally
at home using them? A computer is programmable;
that is, what the computer does depends on the program the computer is
using. (A program
is a list of instructions telling the computer what to do.) A computer's
hardware--the
machine and its components--is designed to be as flexible as possible.
By using computer programs, called software,
you transform this flexible hardware into a tool for a specific purpose.
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No matter which program a computer is using, the machine itself performs only four basic operations. The most widely accepted definition of the computer includes the following operations:
Input.
A computer accepts data that is provided by means of an input
device, such as a keyboard.
Processing.
A computer performs operations on the data to transform it in some way.
Output.
A computer produces output on a device, such as a printer or monitor, that
shows the results of processing operations.
Storage.
A computer stores the results of processing operations for future use.
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This definition is often referred to as the IPOS cycle. The four steps of the IPOS cycle--input, processing, output, storage--don't have to occur in a rigid I-P-O-S sequence. Under the direction of a program, a computer uses the steps of this process when needed and as often as needed.
The use of a personal
computer, a computer designed to meet an individual's computing
needs, illustrates these four basic computer operations. You use the keyboard
to input data. The computer's internal circuitry processes the data. You
see the results (output) on the computer's monitor
(the TV-like display), and you can print these results on the printer.
You can also store the results on the computer's internal disk or on a
removable disk.
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The Computer: Its Uses The purpose of the computer is to transform data into information. In this context, data means some kind of unorganized material that can be entered into the computer--a rough sketch that needs work, a first draft of an essay that needs revision or polishing, figures from a company's books, a list of names and addresses. What results from processing operations is information, data that has been made meaningful and useful.
For example, with the right software, you can use a computer to do your income taxes. You begin by inputting all the data concerning your wages, the amounts withheld from your paycheck, and the amounts of your exemptions and deductions. The computer processes this data and produces output that looks just like the forms used by the Internal Revenue Service (IRS). And what's the information? All the data that you have input has been processed to produce the form for the IRS and the key figure--the amount of your tax refund or the amount you owe. You can then print and store the results.
This capability to process data can be used in a variety of ways. People have come up with some very interesting uses:
Today's dairy farmers are
using computers to optimize feeding times, resulting in gains of up to
30 percent in milk output. Dairy farmers produce as much milk today as
they did 30 years ago, but with fewer cows, lower costs, and less pollution.
The Federalist Papers
are some of America's most important historical documents, but some of
the articles weren't signed. Who wrote them? Using computers to analyze
the writing styles of James Madison, Patrick Henry, and other known authors
of the Papers, scholars have been able to identify the authors of
the unsigned texts.
A psychologist keeps a computer
in the counseling room. At the touch of a key, the psychologist can search
through references on a computer disk for information relating to topics
that come up during counseling sessions.
The Five Elements of the Computing Process Computers consist of hardware, the physical parts of the computer, and software, the programs that tell the computer what to do. Processing data into information (the computing process) involves more elements than just hardware and software, though. And all these elements must be organized so that each works smoothly and efficiently with the others. During the computing process, computers integrate the use of five key elements:
Hardware
Software
Data
People
Procedures
The computing process, in short, includes everything and everyone necessary for the computer to perform a useful task. The following sections show how each of these elements works in the process.
Hardware The term hardware refers to the physical parts of the computer. Computer hardware is versatile--what it does depends on the computer program you use.
The key to the computer's versatility is memory.
You can think of memory as a temporary workspace. The computer's processor
uses this workspace as a scratch pad during processing.
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Many people confuse memory with storage. Memory is temporary. When you turn off the computer, everything in memory is lost. Storage is usually permanent. On most computers, storage also has far greater capacity than memory.
Understanding the distinction between memory and storage is essential. Some programs keep their output in memory. You must transfer the information to a storage device, such as a disk drive, if you want to keep the information permanently. If you switch off the computer without saving this information (transferring it to storage), the information is lost. More than a few students have stayed up all night to finish a paper, only to lose all their work because they didn't understand this distinction.
The key to the computer's precision is the fact that it represents data digitally. Computers use binary digits, which are numbers using a base 2 number system rather than a decimal (or base 10) number system. A binary digit, commonly called a bit, has a value of either 0 (zero) or 1 (one). Eight bits are grouped together to represent a character--a letter, number, or special character. This group is called a byte. Many people use the terms character and byte to mean the same thing.
People talk about bytes when they talk about the capacity of computer memories and storage devices. Because one byte equals only one character, these devices must be capable of storing thousands, millions, or even billions of bytes. To describe these large capacities, the terms kilobyte (K), megabyte (M), and gigabyte (G) are used. A kilobyte equals approximately one thousand bytes, a megabyte equals approximately one million bytes, and a gigabyte equals approximately one billion bytes. (The actual number of bytes in a megabyte is slightly higher because computer storage amounts are actually measured in base 2 numbers.)
Software Software is the set of instructions (also called a program) that guides the hardware through its job. The following sections explore additional aspects of software.
Software programs must be written in programming languages. Programmers--people trained in the use of a programming language--write programs.
Before 1952, the only available programming language was machine language, now called a low-level language. A machine language is recognized by a given brand or design of computer processor. Machine language consists of nothing but the 0s and 1s with which the computer works. Machine language is difficult to learn, and early programs were few and short.
In 1952, a new low-level programming language called assembly language was introduced. In assembly language, programmers use short letter codes (such as RTJ) that stand for specific machine operations. A program called an assembler translates these codes into machine language so that the computer can carry out the instructions. Assembly language is easier than machine language, but by contemporary standards, assembly language is difficult to use. The programmer in assembly language must pay careful attention to how the machine works.
In the 1960s, high-level programming languages emerged. With a high-level language, the programmer uses simple English words and familiar mathematical expressions. The programmer is free to concentrate on the desired result--what the program is supposed to accomplish--rather than worry about the details of how the computer operates.
System and Application Software Packages
Today's complex computer programs, such as Microsoft Word (a word processing program), consist of many separate programs that are designed to run together. In recognition of this fact, people sometimes speak of software packages. When you buy Microsoft Word, you are actually buying a software package rather than a single program.
Based on the function of the package, software packages are divided into two categories: system software and application software. Computer literacy involves learning how to use both system software and one or more application programs.
Computers need system software to function. System software integrates the computer's hardware components and provides tools for day-to-day maintenance tasks, such as displaying a list of the files contained on a disk. MS-DOS, UNIX, Microsoft Windows 95, and System 7 are well-known examples of system software.
Application software turns the computer into a tool for a specific task, such as writing. Not all application programs will prove useful to you. Some application programs are special-purpose programs, which perform a specific task for a single profession. For example, safety managers use a program that prints records of occupation-related injuries and illnesses in a format required by a Federal regulatory bureau. If you aren't a safety manager, you won't find this application program interesting or useful.
Other application programs are called general-purpose programs. Millions of people use these programs for a variety of tasks. Commonly used general-purpose programs include the following:
Word
processing. More than 85 percent of the personal computers now in existence
are equipped with a word processing program, which transforms the computer
into a tool for creating, editing, proofing, printing, and storing text.
Many of today's books originated in text typed into computers--including
this one!
Desktop
publishing. In the past, newsletters and magazines were created through
an expensive, tedious process called layout, in which someone cut and pasted
photographs, borders, and text to create a pleasing design. With desktop
publishing software and your computer, you can produce attractive results
with a little special training. Community organizations everywhere are
doing a better job of keeping in touch with their members, thanks to desktop
publishing tools.
Electronic
spreadsheet. Businesses previously worked out budgets and made forecasts
using accountant's paper and a calculator. Electronic spreadsheet programs
enable you to type the headings and numbers into a computerized version
of accountant's paper, but with a twist. You can hide formulas within the
on-screen "paper." These formulas perform computations with the
data. The payoff is that you can change any number and immediately see
the effect of the change. People use electronic spreadsheets for many purposes,
not just business-related ones. In California, for example, a forest ranger
uses an electronic spreadsheet to analyze data concerning endangered animal
populations.
Database.
A database program creates an electronic version of a card file--and the
program gives you the tools you need to organize this file (for example,
by alphabetizing it) and to retrieve information. An eighth-grade English
teacher, for instance, could create a database of interesting uses of language--and
retrieve examples for use in class discussions.
Telecommunications
software. Do you want access to computer resources available elsewhere?
Telecommunications software transforms a computer into a terminal, which
can connect to a multiuser computer system by means of the telephone. Commercial
multiuser systems enable you to join discussion groups, exchange mail with
other users, make plane and hotel reservations, and obtain free software
for your computer.
Graphics
software. Is there a public presentation in your future? If so, you
need to learn how to use presentation graphics programs to create attractive
charts and graphs that you can share with your audience.
Web browsers are software that search for key words or data
in a collection of files. Netscape Navigator and Microsoft Internet Explorer
are popular Web browsers. |
Resource
discovery software. Currently, the latest wrinkle in application software
is a set of tools for exploring the riches of the Internet, a global network
of linked computer networks. Such tools as Archie, Gopher, and the World
Wide Web help you find computer resources available on millions of publicly
accessible computers throughout the globe.
Data 
The Information Superhighway is a proposed system of computer
networks used to transmit information. The builders of the Information
Superhighway are constantly working to improve the access, speed, quality,
and amount of information transmitted. The Internet, which you learn about
in this textbook, is a prototype for this superhighway. |
Computers transform data into information. What's the difference
between these two terms? Data is the raw material; information
is processed data. Data is the input to the processing; information is
the output.
A useful model to describe the relationship between data and information
is called the
systems model. It shows that data goes into a process and information
is then output.
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Several characteristics distinguish useful information from data. The purpose of information is to help people make well-informed decisions, but what makes information useful? Information must be relevant, timely, accurate, concise, and complete in order to be useful. Data must be accurate but doesn't need to be relevant, timely, or concise. Table 1A.1 describes these characteristics.
| Relevant | Information applies to the current situation. |
| Timely | Information is up-to-date and available when it is needed. |
| Accurate | Data given to the computer and the output are correct in every detail. |
| Concise | Information is condensed into a usable length. |
| Complete | All important items are included. |
People You may be surprised to learn that people are part of the computing process. Some computers, such as the computer chip that controls an automobile engine, function without human intervention. But even these computers were designed by people and occasionally require maintenance by people. Most computers require people, who are called users (or sometimes end users).
Some users progress beyond the basics of computer literacy. They learn the advanced features of application programs. With this knowledge, these users can customize an application program for a specific task. These knowledgeable people are called power users.
Computer professionals have taken intermediate and advanced courses about computers. These people apply their professional training to improve the performance, ease of use, and efficiency of computer systems. One kind of computer professional is the programmer, who creates new computer programs. Excellent career opportunities exist for students interested in becoming computer professionals.
Procedures Procedures are the steps that you must follow to accomplish a specific computer-related task. Part of a user's computer literacy is knowing common procedures.
Chances are, you already know several computer procedures. For example,
you have probably used an automated teller machine (ATM). Inside the ATM
is a computer. In response to on-screen messages called prompts,
you insert your card, enter your personal identification number (PIN),
and tell the machine how much money you want. You also follow computer
procedures when you program your VCR or set the coffee pot to brew your
coffee at 7:00
The Computer: Its Advantages No matter where computers are found or how they are applied, they're
used for input, processing, output, and storage. But computers wouldn't
be worth the trouble without the following characteristics:
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They are fast.
Many of today's computers can perform hundreds of millions of processing
operations in one second.
They are reliable.
Today's computers may run day in and day out for years without failure.
They are accurate.
The computer's physical processing circuits rarely make errors. Computers
make errors, of course, but they are almost always due to faulty programs
or incorrect data input.
They can store massive
amounts of information. Today's personal computers can be equipped
with disks capable of storing more than one billion characters (letters
or numbers). That capacity is enough to store the complete works of William
Shakespeare, an unabridged English dictionary, a 32-volume encyclopedia,
a world atlas and almanac, dozens of computer programs, and all your written
work from the third grade through graduate school--with room for more.
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GIGO stands for 'garbage in, garbage out' and is used to
indicate that humans are the source of most 'computer errors.' |
They can move information
very quickly from one place to another. Using an experimental connection
that may soon play a role in the Information Superhighway, one computer
can send the entire text of the Encyclopedia Britannica to another
linked computer in less than one second.
People like to think of the computer as a useful tool. A computer-literate person knows that the computer is a tool for creating useful information that can be printed, communicated to others, and stored for future use.
Computers come in many sizes. Supercomputers are highly sophisticated computers that perform complex calculations very quickly; supercomputers are most often used for scientific research. Mainframe computers are large, expensive computers designed to meet a large organization's computing needs. Minicomputers are smaller than mainframes but still large enough to meet the computing needs of a medium-sized or small organization. Personal computers, or microcomputers, meet the computing needs of individuals. Notebook computers provide a personal computer's capabilities in a small, lightweight, portable package. All around us are embedded computers, special-purpose computers that perform control functions in such devices as microwave ovens, fuel-injection systems, and wristwatches.
Positive and Negative Effects Computer literacy means learning fundamental computer concepts and application programs. Computer literacy means also recognizing both the positive and the negative consequences of computers in our society.
The positives are all around us. For example, a rescue squad has reduced its emergency response time by nearly 20 percent by using a custom-designed computer system that optimizes its operations. For some accident victims, the difference is literally a matter of life or death. Computers also ease your daily activities by brewing your coffee, printing your newspaper, and helping you write your letters and pay your bills.
But there are negatives too:
Computers may pose a threat
to personal privacy, because firms can so easily accumulate a detailed
picture of an individual's buying habits.
Computer manufacturing
processes require the use of hazardous chemicals, which could endanger
workers and pollute water supplies.
Discarded computers are
taking up too much room in our nation's landfills.
Too much work at the computer
can result in painful nerve injuries, such as carpal tunnel syndrome, the
fastest growing type of occupational injury in the U.S.
Computer failures do occur--and
if they occur in a critical system, such as the air traffic control system,
lives may be endangered.
Computers may displace
workers by automating tasks that people used to perform or by enabling
fewer workers to perform tasks more efficiently. Displaced workers may
find jobs that pay substantially less--if they can find jobs at all.
Like it or not, computers are part of our lives. A good grounding in computer concepts and applications can help you get the benefits and understand the negatives of the computer's massive penetration into society.
Lesson Summary Computers have changed
the way we view our lives. Understanding the fundamental concepts of how
computer systems are set up and how they work, as well as how to apply
the computer to various tasks, contributes to computer literacy.
Some people who are not
computer literate have cyberphobia--a fear of computers.
A computer is a tool that
can manipulate data. You can use software (lists of instructions) to instruct
computer hardware (the machine and its components) to do a variety of tasks
that involve processing data.
The cycle that the computer
hardware and software follows is known as the IPOS cycle. Input is the
data that goes into a process, supported by storage, where the input is
converted into output.
The computing process
can be described in terms of five elements: hardware, software, data, people,
and procedures.
Hardware is the equipment--it
includes storage and memory. Memory is temporary whereas storage is permanent.
Hardware works with digital
units. The digits are kept in binary form, with each binary digit (called
a bit) being placed in either memory or storage.
The characteristics of
computers that give them their power are speed, reliability, accuracy,
storage capacity, and the capability to move data quickly from one place
to another.
Hardware comes in various
sizes, but the most common types are supercomputers, mainframes, minicomputers,
microcomputers, and embedded microprocessors.
Software, or programs,
gives computers their flexibility. When a task is needed, the instructions
for it are loaded into memory. When the task is completed, a different
program can be loaded to do a different task.
The basic language of
the computer is machine language, but it is in binary form and extremely
difficult to work with. Assembly languages were developed to simplify working
with machine languages. High-level languages were developed to make programming
available to most people.
Software packages are
of two types: system software, which works directly with the hardware to
maintain the computer system; and application software, which accomplishes
either a specific or a general task.
General-purpose application
software includes word processing, electronic spreadsheets, graphics, communications,
and database programs.
Data is input to the computer
so that it can be transformed into information. To be useful, information
must be relevant, timely, concise, accurate, and complete.
People who use computers
can be users (or end users), power users, or computer professionals. Whatever
their role, people provide the direction for the hardware and software
to process the data.
Procedures are the steps
that you take to have the computer do the necessary processing.
Using computers has both
positive and negative effects on our lives. Your goal is to take advantage
of the positives and either reduce the negatives or deal with their results
in the best way for you.
Laboratory Exercises
Lesson
Review
Further Discovery Computer Science: An Overview, Fifth Edition. J. Glenn Brookshear (Redwood City, CA: Benjamin/Cummings, 1997).
How Computers Work. Ron White (Emeryville, CA: Ziff-Davis, 1995).
IBM Dictionary of Computing (New York: McGraw-Hill, 1994).
Que's Computer & Internet Dictionary, 6th Edition. Bryan
Pfaffenberger (Indianapolis, IN: Que, 1995).
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Online Discovery You can access the Internet resources for the following questions by going to the Que Education and Training Web site at URL http://www.mcp.com/queet/ciyf/onlinelinks.html. From this page, click the link for Lesson 1A and then click the link to the resource you want to access.
1. Because the Internet was originally created and used by computer experts, a lot of information about computers and computing has always been available on the Internet. Yahoo! is an Internet directory service that collects useful Internet resources--sort of a Yellow Pages for the Internet. Use the Yahoo! directory page on Computers and Internet (http://www.yahoo.com/Computers_and_Internet) to explore the many uses, forms, and suppliers of computers and computer-related services. Do you find anything that surprises you? What different types of computers can be found in these resources? After looking through many of these resources, name four different uses of computers that you discover, as well as four different types of businesses related to computers. How do these businesses differ?
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2. Computers seem to generate the use of jargon and many abbreviations. Although some of these words are eventually integrated into standard English, most of them remain a mystery to most people. Computing dictionaries, such as the Free On-line Dictionary of Computing (http://wfn-shop.princeton.edu/cgi-bin/foldoc) can help dispel some of the mystery. Take a look at this dictionary and try to learn at least four different computer-related terms or abbreviations.
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A note about Online Discovery. The Online Discovery section, found at the end of each lesson, gives you the opportunity to use the World Wide Web to explore in more detail some of the topics discussed in the lesson.
To be able to access the sites described in Online Discovery, you will need access to the World Wide Web. You may have access in a number of different ways, depending on your particular setup. You may, for example, access the Web through a commercial online service such as America Online, CompuServe, or Prodigy. If you get access to the Internet through your college or university, or through a local Internet service provider, you probably have a direct connection to the Internet; in this case, you access the Web through a browser program such as Netscape Navigator, Microsoft Internet Explorer, or Mosaic. Finally, certain types of Internet accounts provide access to the Web through a text-only program called Lynx. If your account provides text-only access, you will be able to access the sites mentioned in Online Discovery, but you might not be able to access all the information present; with text-only access, you will not be able to view graphics.
In the Online Discovery sections, the addresses of all the Internet resources and home pages mentioned in the examples are provided. These addresses are in the form of URLs, or Uniform Resource Locators, which are sort of like street addresses of pages on the Internet.
The URL of the Macmillan Computer Publishing home page, for example, is http://www.mcp.com. You can enter this address into your Web browser to retrieve and view the Macmillan Computer Publishing home page. The way in which you enter addresses and view documents will vary depending on the Web browser you are using. In Netscape Navigator, you simply click the button labeled Open, and in the box that appears, you type the address of the document you want to view.
Although the addresses of all the resources mentioned in the Online Discovery sections are provided for you in the examples, you can also access all these addresses directly from the Que Education and Training Web page that has been set up for you, at URL http://www.mcp.com/queet/ciyf/onlinelinks.html. If you enter this address into your Web browser, you can then follow links that will lead you to all the resources mentioned in Online Discovery.
At the time of this book's publication, the Web sites used in the examples were accessible, but some sites may have been closed or moved to new locations. If you have any difficulty getting access to the World Wide Web or to any of the resources in Online Discovery, you should ask your instructor for help.
Related Web Sites
