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The Internet and World Wide Web
We begin with a brief history of the Internet and World Wide Web. We describe how Web documents are accessed and created, and define basic terms such as HTTP (HyperText Transfer Protocol) and HTML (HyperText Markup Language).
The World Wide Web cannot be appreciated, however, until you visit it yourself. Thus, the chapter also introduces Internet Explorer, the browser that was developed by Microsoft. As always, learning is best accomplished by doing, and so we include two hands-on exercises and provide our own guided tour so that you can experience firsthand what the excitement is all about.
The Internet
The Internet is a network of networks that connects computers across the country and around the world. It grew out of a U.S. Department of Defense (DOD) experimental project begun in 1969 to test the feasibility of a wide area (long distance) computer network over which scientists and military personnel could share messages and data. The country was in the midst of the Cold War, and the military imposed the additional requirement that the network be able to function with partial outages in times of national emergency (e.g., a nuclear disaster), when one or more computers in the network might be down.
The proposed solution was to create a network with no central authority. Each node (computer attached to the network) would be equal to all other nodes, with the ability to originate, pass, and receive messages. The path that a particular message took in getting to its destination would be insignificant. Only the final result was important, as the message would be passed from node to node until it arrived at its destination.
The experiment was (to say the least) enormously successful. Known originally as the ARPAnet (Advanced Research Projects Agency network), the original network of four computers has grown exponentially to include tens of millions of computers at virtually every major university and government agency, and an ever increasing number of private corporations and international sites. To say that the Internet is large is a gross understatement, but by its very nature, it's impossible to determine just how large it really is. How many networks there are, and how many users are connected to those networks, is of no importance as long as you yourself have access.
The Internet is a network of networks, but if that were all it were, there would hardly be so much commotion. It's what you can do on the Internet, coupled with the ease of access, that makes the Internet so exciting. In essence, the Internet provides two basic capabilities, information retrieval and worldwide communication, functions that are already provided by libraries and print media, the postal system and the telephone, television, and other types of long-distance media. The difference, however, is that the Internet is interactive in nature, and more importantly, it is both global and immediate.
TCP/IP
Data is transmitted from one computer to another across the Internet through a series of protocols known collectively as TCP/IP (Transmission Control Protocol/Internet Protocol). You can progress quite nicely through our text without knowing anything more about TCP/IP. We do, however, provide an appendix in case you are curious about the internal workings of the Internet.
The Internet enables you to request a document from virtually anywhere in the world, and to begin to receive that document almost instantly. No other medium lets you do that. Television, for example, has the capability to send information globally and in real time (while events are unfolding), but it is not interactive in that you cannot request a specific program. Federal Express promises overnight delivery, but that is hardly immediate. The books in a library provide access to the information that is physically in that library, but that is not global access. Indeed, the Internet, and in particular, the World Wide Web is truly unique.
The World Wide Web
The original language of the Internet was uninviting and difficult to use. The potential was exciting, but you had to use a variety of esoteric programs (such as Telnet, FTP, Archie, and Gopher) to locate and download data. The programs were based on the Unix operating system, and you had to know the precise syntax of the commands within each program. There was no common user interface to speed learning. And, even if you were able to find what you wanted, everything was communicated in plain text, as graphics and sound were not available. All of this changed in 1991 with the introduction of the World Wide Web.
The World Wide Web (WWW or, simply, the Web) can be thought of as a very large subset of the Internet, consisting of hypertext and/or hypermedia documents. A hypertext document is a document that contains a hyperlink (link) to another hypertext document, which may be on the same computer or even on a different computer, with the latter located anywhere in the world. Hypermedia is similar in concept, except that it provides links to graphic, sound, and video files in addition to text files.
Either type of document enables you to move effortlessly from one document (or computer) to another. Therein lies the fascination of the Web, in that you simply click on link after link to go effortlessly from one document to the next. You can start your journey at your professor's home page in New York, for example, which may link to a document in the Library of Congress, which in turn may take you to a different document, and so on. So, off you go to Washington DC, and from there to a reference across the country or perhaps around the world.
Any computer that stores a hypermedia document anywhere on the Web, and further, makes that document available to other computers, is known as a server (or Web server). Any computer that is connected to the Web, and requests a document from a server, is known as a client. In other words, you work on a client computer (e.g., a node on a local area network or your PC at home) and by clicking a link in a hypermedia document, you are requesting a document from a Web server.
HYPERTEXT TRANSFER PROTOCOL (HTTP)
In order for the Web to work, every client (be it a PC or a Mac) must be able to display every document from every server. This is accomplished by imposing a set of standards known as a protocol to govern the way data is transmitted across the Web. Thus, data travels from client to server, and back, through a protocol known as the HyperText Transfer Protocol (or http for short). In addition, in order to access the documents that are transmitted through this protocol, you need a special type of program known as a browser. Indeed, a browser is aptly named because it enables you to inspect the Web in a leisurely and casual way (the dictionary definition of the word "browse"). Internet Explorer 5.0 (IE5) is the browser we use throughout the text.
Consider, for example, the hypermedia documents in Figure 1. To display these documents on your computer, you would need to be connected to the Internet and you would need to know the address of the first document, in this case, www.refdesk.com. (Yes, it helps to know the addresses of interesting Web pages, and we suggest several sites to explore in Appendix B.) We describe the structure of Internet addresses later in the chapter, but for the time being, suffice it to say that every server, and every document on every server, has a unique address. The "http" that precedes the address indicates that the document is being transferred according to the hypertext transfer protocol we discussed earlier.
The first document displayed by a Web site is its home page; thus the document in Figure la is the home page of My Virtual Reference Desk and it is one of our favorite sites on the Web. Not only does it demonstrate the concept of hypertext, but by its very nature it elegantly shows the global nature of the World Wide Web. Once you arrive at a Web page, you can click any link that interests you.
Consider, for example, our path through Figure 1. We began by scrolling down the home page of My Virtual Reference Desk in Figure la until we could click the link to Fast Facts 1998. which in turn displayed the document in Figure Lib. Note how the address changes automatically in the address bar. Indeed, that is what the Web is all about as you move effortlessly from one document to another. We then clicked the link to CarPoint. which took us to an entirely different site in Figure lc. Next, we clicked the link to Sports Cars to display the list of cars in Figure ld. (The CarPoint home page provides graphical links as well as underlined text links; that is, each of the buttons on the left side of the page is a link to the respective category.) We clicked Corvette from the list of sports cars in Figure ld then clicked an additional link to display the specific information about the new car in Figure le. We explored the various links on this page, and then ended with the Buying Service in Figure lf
The underlined links that appear in Figure 1 are displayed in one of two colors, blue or magenta, depending on whether or not the link has been previously selected. Any link in blue (the majority of links) indicates the document has not yet been viewed. Links in magenta, however (such as Fast Facts 1998 in Figure la), imply the associated document has been retrieved earlier in that session or in a previous session. Note, too, the presence of advertising on the Web in the CarPoint screens of Figures Lid and e. The vendors (1-800-FLOWERS and Barnes and Noble) pay the host of the site for advertising space in the hope of enticing the visitor to click the advertisement.
Think for a moment of what we have just accomplished. We started with a general reference page and in a matter of minutes were in the process of purchasing a new car. There is no beginning (other than the starting point or home page) and no end. You simply read a Web document in any way that makes sense to you, jumping to explore whatever topic you want to see next. All of this is accomplished with a graphical browser such as Internet Explorer and a connection between your computer and the Internet.
FIGURE 1 The World Wide Web
SEARCH ENGINES—A LOOK AHEAD
There are two very general ways to navigate through the Web. You can start by entering the address of a specific site such as www.refdesk.com, then once you arrive at the site, you can go leisurely from link to link. Browsing in this manner is interesting and enjoyable, but it is not always efficient. Hence, when searching for specific information, you often need a special tool called a search engine, with which you conduct a keyword search of the Web, much as you search a card catalog or online database in the library. Search engines are discussed in Chapter 2.
Internet Explorer is easy to use because it shares the common user interface and consistent command structure present in every Windows application. Look, for example, at any of the screens in Figure 1 and you will see several familiar elements. These include the title bar, minimize, maximize (or restore), and close buttons. Commands are executed from pull-down menus or from command buttons that appear on a toolbar under the menu bar. A vertical and/or horizontal scroll bar appears if the entire document is not visible at one time. The title bar displays the name of the document you are currently viewing.
THE UNIFORM RESOURCE LOCATOR (URL)
The location (or address) of the document appears in the Address bar and is known as a Uniform Resource Locator (URL), or more simply as a Web address. The URL is the primary means of navigating the Web, as it indicates the address of the Web server (computer) from which you have requested a document. Change the URL (e.g., by clicking a link or by entering a new address in the Address bar) and you jump to a different document, and possibly a different server.
A URL consists of several parts: the method of access, the Internet address of the Web server, an optional path in the directory (folder) structure on the Web server to the document, and finally the document name. (Some URLs do not include the document name, in which case the browser displays a default document, typically called index.html.) Each time you click a link, you are effectively entering a new address with which to connect. The general format of a Web address is:
The components in the address can be read from right to left. In other words, the preceding address references the document 120Hp.html (the document name is case-sensitive) in the -rgrauer directory on the Web server www.bus.miami.edu according to the http protocol. (This document is the home page for Bob's introductory computer course at the University of Miami.)
To go to a particular site, enter its address through the Open command in the File menu or type the address directly in the Address bar, press the enter key, and off you go. Once you arrive at a site, click the hyperlinks (underlined items or graphical icons) that interest you, which in turn will take you to other documents at that site or even at a different site. The resources on the Web are connected in such a way that you need not be concerned with where (on which computer) the linked document is located.
WHAT IS HTML?
All hypertext and hypermedia documents are written in HTML (HyperText Markup Language) and display the extension html at the end of the document name in the Web address. You will, however, see an extension of htm (rather than html) when a document is stored on a server that does not support long file names. Unix-based systems, which constitute the majority of Web servers, support long file names, and so html is the more common extension.
Connecting To The Internet
There are two basic ways to connect to the Internet—from a local area network (LAN) or by dialing in. It's much easier if you connect from a LAN (typically at school or work) since the installation and setup has been done for you, and all you have to do is follow the instructions provided by your professor. If you intend to dial in from home, however, you will need a modem and an Internet Service Provider. A modem is the hardware interface between your computer and the telephone. In essence you instruct the modem, via the appropriate software, to dial the phone number of your ISP, which in turn lets you access the Internet.An Internet Service Provider (ISP) is a company or organization that maintains a computer with permanent access to the Internet. Typically, you have to pay for this service, but you may be able to dial into your school or university at no charge. If not, you need to sign up with a commercial vendor such as America Online (AOL). Not only does AOL provide access to the Internet, but it also offers a proprietary interface and other services such as local chat rooms. The Microsoft Network (MSN) is a direct competitor to AOL, and it, too, offers a proprietary interface and extra services. Alternatively, you can choose from a host of other vendors who provide Internet access without the proprietary interface of AOL or MSN.
Regardless of whom you choose as an ISP, be sure you understand the fee structure. The monthly fee may entitle you to a set number of hours per month (after which you pay an additional fee), or it may give you unlimited access. The terms vary widely, and we suggest you shop around for the best possible deal. In addition, be sure you are given a local access number (i.e., that you are not making a long-distance call), or else your telephone bill will be outrageous. Check that the facilities of your provider are adequate and that you can obtain access whenever you want. Few things are more frustrating than to receive continual busy signals when you are trying to log on.
DISABLE CALL WAITING
Your friend may understand if you excuse yourself in the middle of a conversation to answer another incoming call. A computer, however, is not so tolerant and will often break the current connection if another call comes in. Accordingly, check the settings of your communications program to disable call waiting prior to connecting to the Internet (typically by entering *70 in front of the access number). Your friends may complain of a busy signal, but you will be able to work without interruption.
Learning By Doing
The Web cannot be appreciated until you experience it for yourself, and so we come to our first hands-on exercise, which takes you to the Web site of the national newspaper USA Today. You are accustomed to reading a newspaper in conventional fashion, perhaps with a morning cup of coffee. Now you can read that paper (and countless others) in an entirely different way. We suggest a specific starting point (the home page of USA Today) and a progression through that document. You will not, however, see the exact figures in our exercise because the Web is changing continually. Note, too, that you can start with any other home page and choose any set of links to capture the spirit of the exercise. Going from one document or link to the next is what the World Wide Web is all about. Enjoy.
INTERNET EXPLORER 5.O
We trust that you enjoyed the hands-on exercise and that you completed it without difficulty. Our objective was to get you up and running as quickly as possible so that you could experience the Web and appreciate its potential. Internet Explorer 5.0 (IE5) is easy to use because it is a Windows-based program that follows the common user interface. The next several pages examine Internet Explorer in more detail to help you use the program effectively.
Figure 2a displays the home page of Microsoft Corporation as it appears with the default settings of Internet Explorer. Figure 2b displays a different view of the same page (the address is the same in both figures) in order to illustrate additional features within Internet Explorer. The most obvious difference betweenthe two is the display or omission of the graphics, which enhance the appearance of a page, but increase the time it takes to download the page and display it on your PC. The presence or absence of the graphics is controlled through the Internet Options command in the Tools menu, one of several pull-down menus within Internet Explorer.
FIGURE 2 Internet Explorer
The menu bar provides access to all commands within Internet Explorer. Some menus (File, Edit, View, and Help) are common to most Windows applications, whereas others (Go and Favorites) are unique to Internet Explorer. The Favorites menu is especially important, as it enables you to store the addresses of your favorite pages in order to return to those pages at a later date.
The Help menu in Internet Explorer is similar to that of other applications. The Contents and Index command presents a tabbed dialog box with three tabs— Contents, Index, and Search. The Help menu also provides a link to online support, which takes you to the Microsoft Web site that contains up-to-the-minute information. Help is illustrated in detail in the hands-on exercise that follows shortly.
The toolbars offer an alternate way to execute the most common commands. The Standard Buttons toolbar in Figure 2a displays both text and graphic icons. The Standard Buttons toolbar in Figure 2b, however, displays only the graphic icons and thus provides additional space within the Internet Explorer window to view the actual document. The appearance of the toolbar is controlled through the Toolbars command in the View menu.
The Address bar displays the address of the page you are currently viewing (http://www.microsoft.com in both Figure 2a and 2b), and its contents change automatically whenever you click a hyperlink to a different page. You can also click in the Address bar to enter an address manually, after which you press the Enter key to access that page.
Links (short for hyperlinks) and hot spots provide connections to other documents. A link appears as underlined text. Hot spots are hyperlinks that have beeij embedded within a graphic (e.g., Office 2000 on Tour in Figure 2a) as opposed to appearing as underlined text. The mouse pointer changes to a hand when pointing to a link or hot spot.
The status bar at the bottom of the window displays information about the current operation. If, for example, Internet Explorer is in the process of retrieving a document, the status bar will show the progress of the file transfer, such as "Done" in Figure 2a. Alternatively, the status bar will display the underlying address whenever you are pointing to a link or hot spot.
RETURNING TO A PREVIOUS SITE
Internet Explorer enables you to move effortlessly from one Web document to another. As you browse through the Web, it's all too easy to forget how you arrived at a particular site, making it difficult to return to that site at a later time. You could click the Back button repeatedly, but that is somewhat tedious, and further, it works only for the particular session. What if you wanted to return to a site you visited last Monday? Internet Explorer anticipates the problem and provides two different sets of links, the Favorites list and the History list.
The Favorites list in Figure 2a consists of sites that you save with the expectation of returning to those sites at a future time. Once you arrive at a site that you consider special, just pull down the Favorites menu and click the Add to Favorites command. Internet Explorer then creates a link to that site within the Favorites list. The links can be stored individually (e.g., NTSB - Home Page), or they can be stored with related links in a folder (e.g., Microsoft Links). The typical user starts by creating individual links, then eventually opts for folders to organize the links more efficiently.
FIGURE 3 Returning to a previous site
The History list in Figure 3b is even easier to use in that the links are created automatically and consist of all sites that were visited during a specified time span. (The default is 20 days.) The links in the History list are organized automatically into subfolders, one for today, one for each day of the current week, then a separate folder for previous weeks. The links are further divided to show the site (e.g., www.microsoft.com), then the pages at that site.
Either list can be displayed by clicking the appropriate button on the Standard Buttons toolbar. The lists can also be accessed via the Explorer bar command in the View menu. In either case, the browser window is divided into two panes. The left pane displays the links in a specific list (such as History or Favorites). The right pane displays the selected Web page. The Explorer bar is illustrated in our next exercise.
SET A TIME LIMIT
The exercise you are about to do has you browse continually, looking for interesting sites on which to hone your skills. We warn you that the Web is addictive, and that once you start surfing, it is difficult to stop. We suggest, therefore, that you set a time limit before you begin, and that you stick to it when the time has expired. Tomorrow is another day, with new places to explore.
SUMMARY
The Internet is a network of networks. The World Wide Web (WWW or simply the Web) is a very large subset of the Internet, consisting of hypertext and/or hypermedia documents.
A hypertext document is a document that contains a link to another document, which may be on the same computer or a different computer, with the latter located anywhere in the world. Hypermedia provides links to graphic, sound, and video files in addition to text files. All hypertext and hypermedia documents are written in HyperText Markup Language (HTML).
The Web uses a client/server model in which every client must be able to display every document from every server. A computer that stores (and provides access to) a hypermedia document is called a server. A computer that requests a document is called a client. Data travels from server to client and back through a protocol known as the HyperText Transfer Protocol (or HTTP for short).
A program known as a browser is required to view documents transmitted through the HTTP protocol. Internet Explorer 5.0 is the browser included in Microsoft Office 2000.
Internet Explorer is easy to use because it shares the common user interface and consistent command structure present in every Windows application. Commands are executed from pull-down menus or from command buttons that appear on a toolbar under the menu bar.
The location (or address) of the Web page appears in the Address bar and is known as a Uniform Resource Locator (URL). A URL consists of several parts: the method of access, the Internet address of the Web server, the path in the directory (folder) structure on the Web server to that document, and the name of the document.
There are two basic ways to connect to the Internet—from a local area network (LAN), or by dialing in. To dial in—for example, to connect from home— you need an Internet Service Provider, a company or information service that enables you to access the Internet via a modem.
Your exploration of the World Wide Web is limited only by your imagination. You can obtain a list of interesting sites to visit by clicking various links on the Links toolbar. Alternatively, you can enter the address of a specific site directly in the Address bar.
Internet Explorer provides two different ways to return to previous sites— the Favorites list and the History list. The links in the Favorites list are added by the user through the Favorites menu. The links in the History list are created automatically by IE4 and are organized into folders—one folder for today's sites, one folder for each day of the current week, then a separate folder for previous weeks. Either list can be displayed by clicking the appropriate button on the standard toolbar.
FINDING INFORMATION ON THE WEB
The Internet contains a wealth of information that is readily available. That's the good news. The bad news is that the Internet contains so much information that it is often difficult to find what you are looking for. Browsing, while interesting and enjoyable, is not a very efficient way to locate specific information. This chapter introduces the concept of a search engine, a program that systematically searches the Web for documents on a specific topic.
We begin with an explanation of how search engines work and why they are essential. You will learn that many search engines are available and that the same query can return different documents via different engines
You will find that a search often yields too many documents (hits) that are only marginally relevant to your query. You will also learn that a search that is too specific may not yield any documents at all, making it necessary for you to use multiple engines for the same query.
Suffice it to say, therefore, that searching is a trial and error process. Accordingly, the chapter describes a variety of search techniques to maximize your chance for success. We explain why it is important to use several different search engines. We introduce the concept of Boolean operations and describe how to qualify a search using different logical operators. We also distinguish between searching the Web versus searching a specific site; for example, you may search the Web to locate an online bookstore, then search the resulting site to find a specific book. As always, the chapter gives you the opportunity to apply the conceptual information through hands-on exercises at the computer.
AVOID TRAFFIC JAMS
Rush hour traffic is always tedious, whether you are on the city streets or the Information Superhighway. Sometimes it can't be helped, in that you have to go to work at a certain time or use the computer lab when it's open. Try, however, to avoid the peak hours during the middle of the day when traffic on the Web is busiest and response time is very slow. Go to the lab early in the morning or late at night. Not only will you (almost certainly) be guaranteed a computer, but you will avoid rush hour on the Internet as well.
SEARCH ENGINES
The same techniques apply to effective research, regardless of whether it is done in the library or on the World Wide Web (although the Web has made the task much easier). If, for example, you were using the library to do research for a term paper, you wouldn't do very well by randomly strolling through the stacks from floor to floor until you found what you wanted. It's equally inefficient to just browse through the Web, going from one link to another until you stumble onto a relevant document.
It's obvious that you would do much better in both cases to conduct a key word search, in which you look for documents on a specific topic. In yesterday's library you would look up the topic in the card catalog; in today's library you would use an online database, and on the Web you would use a search engine, the Web's equivalent of the library's card catalog or database.
A search engine is a program that systematically searches the Web for documents on a specific topic. You enter a query (a key word or phrase) into a search form, and the search engine scans its database to see which documents (if any) are related to the key word you requested. The search engine will list the titles of the documents it finds, together with a link to each document. Some search engines also display an abstract of each document to help you determine its relevancy to your query.
Many search engines are available, each of which uses its own database of Web documents. Each database stores information about each document it contains, typically the document's URL (i.e., its Web address), key words that describe the document, and selected information from the document. Some databases store only the document's title, others contain the first few lines of text, and still others contain every word in the document. Each engine uses its own version of a special program known as a spider to automatically search the Web on a periodic basis, looking for new pages to add to its database.
Some search engines are better than others, but there is no consensus on the "best" engine. In any event, a search engine is only as good as its database and the algorithm it uses to search that database for relevant documents. The larger the database, the greater the number of hits (documents matching your query) that are returned.
A large number of hits, however, does not necessarily guarantee a successful search, because you also need to be concerned with the relevancy of those hits. In other words, the mere fact that a document contains a key word or phrase does not mean the document is useful to you. If, for example, you were searching for information on airline reservations, you might not be interested in the home page of a specific travel agent. And while you might be interested in the home page of a specific airline, you might be better served by a document that lets you access the flight schedule of several airlines.
Assume, for example, that you are planning a trip and that you want the cheapest and/or most convenient flight from Fort Lauderdale to San Francisco. Any query that specific, however, would be unlikely to return any hits at all. You might begin, therefore, by searching the Web for a site that lets you make an airline reservation, then once you found such a site, search for the specific flight. The process is illustrated in Figure 4.
The easiest way to initiate a search is to click the Search button on the Standard Buttons toolbar. This opens the Explorer bar and displays the Search pane that is visible in Figures 4a and 4b. The latter contains a text box in which you enter the search criteria, after which you see the results of the search. We selected the Lycos and Infoseek engines in Figures 4a and 4b, respectively, and used the same query, "airline reservations," for both.
The results of the search are displayed as a series of links underneath the list box. The results are different because each engine uses a different database, as well as a different search algorithm. In other words, the same query produces different results with different engines, and thus it is important to use multiple engines for the most complete results. Note, too, that you can click any link in the left pane to display the corresponding document in the right pane.
The document in Figure 4b looked promising, so we decided to explore it further. We were required to enter a personal profile, obtain a username and password, but there was no charge to do so. We were then able to enter the parameters of our desired flight in Figure 4c, after which we were presented with a series of flights that met our requirements in Figure 4d. There was no obligation, whatsoever. We could make the reservation online through the Travelocity site, we could call the airline to make the reservation directly, or we could contact a travel agent to do it for us.
The point of this example is not to make an actual reservation, but to illustrate the mechanics of searching the Web. Think for a minute about what was accomplished. You were looking for information on a flight from Fort Lauderdale to San Francisco. You used a search engine to look through millions of Web documents for information on airline reservations, which in turn led you to a site that let you search for a specific flight. All of this was accomplished in minutes, and the information you retrieved is as complete as that provided by any airline or travel agent.
This example also illustrates the difference between a generalized Web search versus a specific site search. This two-step approach is very common and is used in a variety of instances. The following exercise has you look for the e-mail address of one of the authors. In so doing, you will search the Web for the University of Miami (the author's place of employment), then search the UM site for information about the author himself. Note, too, that the UM site, like many other universities, provides links to a host of campus information. Hence, you can also use the exercise as a guide to learn more about your own college or university.
FIGURE 4 Searching the Web
FINER POINTS OF SEARCHING
We trust that you completed the hands-on exercise without difficulty and that you have a better appreciation for the research potential of the Web. Searching for information is a trial-and-error process in that there is no guaranteed method for success. The Web may or may not contain the documents you need, and even if it does, there is no assurance that you will be able to find them. Nevertheless, we have been successful more often than not, and patience and common sense will usually prevail.
As we have already indicated, there is no single best search engine. Each engine uses its own database and its own search algorithm, so that the same query will return different results with different engines. Yahoo, for example, may provide the best results with one type of query, whereas a different search engine, such as Excite or Infoseek, will provide better results on a different query. Hence, it is good practice to use at least two different engines on the same query in order to obtain a sufficient number of relevant documents.
Note, too, that any given query can return hundreds (even thousands) of documents, so it is essential to structure queries in such a way as to return only the most relevant hits. In general, the more specific your query, the better. A search on "movies," for example, would be unnecessarily broad if your real interest was "science fiction movies." Conversely, a query that is too specific may not return any documents at all. Thus, as we have said throughout, searching is an iterative process during which you continually refine your search criteria.
LOGICAL (BOOLEAN) OPERATORS
All queries are, in essence, a combination of the logical (Boolean) operators And, Or, and Not. The And operator requires that every key word must be present. Searching for "President" and "Clinton," for example, will return documents about Mr. Clinton's presidency. The Or operator, however, requires that only one of the terms be present, so that searching for "President" or "Clinton" will return documents about presidents (any president) and Clinton (any Clinton). Some search engines also enable you to use Not. Searching for "Bill" and "Clinton," but specifying "Not President," will return documents about other aspects of Mr. Clinton's life and other Bill Clintons. The way in which you specify the Boolean operators depends on the search engine and is described in its online help.
Figure 5 illustrates the use of the Yahoo search engine to look for information about Leonardo da Vinci and the Mona Lisa. Figure 5a shows the Search pane of the Explorer bar in which we entered the parameters of the search using the Yahoo engine. Yahoo uses the Boolean And operation by default and returns those documents that contain references to both Leonardo and da Vinci. The results of the search are displayed below the query. The contents of the selected document (the category in this example) are displayed in the right pane.
THE FIND AND SAVE COMMANDS
The Explorer bar is closed in Figures 5b, c, and d to provide more room in which to examine the various documents in detail. Figure 5b displays a portion of the Leonardo Web Museum document that was listed as a link in Figure 5a. Figure 5b also illustrates the Find command to search for a specific character string within a document. (The Find command is contained in the Edit menu.) In other words, the document in Figure 5b describes da Vinci's life in detail, and the Find command represents the fastest way to locate a reference to the Mona Lisa. Alternatively, you could scroll through the document manually, until you came to the Mona Lisa.
FIGURE 5 Research on the Web
Note, too, the thumbnail images (graphic icons or small versions of a larger image) in Figure 5b that appear in the document rather than the actual drawings. This is a nice touch used by many Web designers who want to include a graphic, but who are considerate enough not to force the visitor to wait for a large image to be displayed each time the page is loaded. Thus, they include a thumbnail image that a visitor can click to bring up the larger graphic as shown in Figure 5c
Once you locate the Mona Lisa, you can download the graphic to your PC in order to include the picture in a document of your own. The easiest way to do this is to right click the graphic to display a context-sensitive menu, as shown in Figure 5c. Select the Save Picture As command, which in turn displays a dialog box in which you specify the drive and folder in which to save the graphic.
After the picture has been downloaded to your machine, you can use the Insert Picture command in Microsoft Word to include the picture in a document of your own, perhaps on the cover page of your paper about Leonardo da Vinci. The Insert Picture Command is not part of Internet Explorer per se, but we think you will find the suggestion very helpful. You can use a similar technique to download graphic images for inclusion in a PowerPoint presentation or Excel workbook.
EXPLORE THE URL
In searching the Web, there is no substitute for common sense and imagination on the part of the researcher. You will find, for example, that a server (Web site) often contains additional documents that may be relevant to your search if only you take the time to look. Consider, for example, the URL of the document in the Figure:
A URL consists of several components in the following sequence: the means of access (typically http), the server (computer on which the document is located), the path on that computer (if any) to travel to the document, and finally the document itself. In other words, we found a specific server (whose address is sunsite.unc.edu) that contained a picture of the Mona Lisa. It's logical to think that the same computer may contain other pictures or information in which we would be interested.
On a hunch (born out of experience) we backed up one level at a time within the address for the Mona Lisa, until we came to the document shown in Figure 5d. This proved to be a bonanza as it placed us in the Web museum, from where we had access to all types of art by a host of other artists. We suggest you take a few minutes to visit the museum.
Aside from being a wonderful way to browse, it may also be a boon to your research, because you are often searching for a concept rather than a specific term. You might, for example, be interested in Renaissance artists in general, rather than just da Vinci, and you have just discovered an invaluable resource.
USE SPECIALIZED ENGINES
There are many ways to search for information. Typically, you begin with a generalized search of the entire Web, which often leads to a specific site that you search in depth. The flight reservation example at the beginning of the chapter fell into this pattern. We began by searching for information about "airline reservations," which led to a specific site that contained a database with information about flights from many airlines. The latter site was what we really wanted, and would be a logical starting point for all future searches on flight availability.
Many specialized databases are available. One such site is My Virtual Reference Desk (www.refdesk.com) that was introduced in Chapter 1. You can go to this site, then explore its links to arrive at a host of specialized searches. Try, for example, the link to acronyms, to access a specialized database that lets you enter an acronym and determine its meaning. You can also enter a word and request a list of all acronyms containing that word.
Figure 6 displays another favorite page in which you search by category as opposed to entering the text of a specific query. Enter the address of the Web site (www.looksmart.com), and then scroll down the left pane until you find the category that you want to explore (Entertainment and Media). Click the subcategory (Movies), click the next subcategory (Movies by Genre), then select the specific movie type.
FIGURE 6 Specialized Searches
BOOKS ONLINE
The Internet Public Library at www.ipl.org/reading contains various links to various books and texts that are freely available over the Internet. The electronic version is fully searchable and thus enables you to research the text as never before. Many of the texts are available as a result of Project Gutenberg (promo.net/pg). These are two sites you don't want to miss.
COPYRIGHT PROTECTION
A copyright provides legal protection to a written or artistic work, giving the author exclusive rights to its use and reproduction, except as governed under the fair use exclusion as explained below. Anything on the Internet or World Wide Web should be considered copyrighted unless the document specifically says it is in the public domain, in which case the author is giving everyone the right to freely reproduce and distribute the material.
Does this mean you cannot quote statistics and other facts that you found on the Web in your term papers? Does it mean you cannot download an image to include in your report? The answer to both questions depends on the amount of the material and on your intended use of the information. It is considered fair use, and thus not an infringement of copyright, to use a portion of the work for educational or nonprofit purposes, or for the purpose of critical review or commentary. In other words, you can use a quote, downloaded image, or other information from the Web, provided you cite the original work in your footnotes and/or bibliography. Facts themselves are not covered by copyright, so you can use statistical and other data without fear of infringement. Be sure, however, to always cite the original source in your document.
COPYING LICENSED SOFTWARE IS BREAKING THE LAW!
The fair-use doctrine does not extend to licensed software, even if you intend your copy to be used for educational use only. You can, however, legally copy licensed software to create a backup copy in case the original is damaged, but that's it. Any other copies are illegal.
SUMMARY
Search engines provide an efficient way to look for information on the World Wide Web. You enter a query consisting of the key words you are searching for, and the search engine responds with a number of "hits," or Web documents that meet the search criteria. Searching is, however, a trial and error process with no guarantee for success.
Many different search engines are available, each of which uses a different database and different search algorithm. Each database stores information about its collection of Web documents (running into the millions) and consists of the document's URL (i.e., its Web address) and information (key words) about what is contained in each document. It is important, therefore, to try different engines with the same query, and further, to continually refine a query during the course of a search.
Any given query (request to a search engine) can return hundreds (even thousands) of documents, so it is essential to structure queries in such a way as to return only the most relevant hits. All queries are, in essence, combinations of the logical operations And, Or, and Not. In general, the more specific your query, the better.
Specialty search engines are also available and enable in-depth searches on a specific topic. Specialty engines can be found through a generalized Web search for a specific topic such as "airline reservations," which in turn leads to several databases with flight information. One can also click the Search button on the Internet toolbar to display a list of specialty engines.
Images can be downloaded from the Web and saved onto a local drive for subsequent inclusion in a document. The Insert Picture command inserts a graphic image into a Word document or PowerPoint presentation.
A copyright provides legal protection to a written or artistic work, giving the author exclusive rights to its use and reproduction. Anything on the Internet or World Wide Web should be considered copyrighted unless the document specifically says it is in the public domain. The fair use exclusion, however, lets you use a portion of the work for educational, nonprofit purposes, provided you cite the original work in your footnotes and/or bibliography.