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CHAPTER 31

Finding and Evaluating Sources
31a What is a source?

A source is any form of information that provides ideas, examples, informa-
tion, or evidence. For a research paper, sources can be books, articles, Web
pages, Internet files, CD-ROMs, videos, lectures, and other types of commu-
nication. Sources can also be interviews, surveys, or direct observations, such
as when you attend a performance or visit a museum. Sources differ greatly in
terms of how accurate and reliable they are. To be able to use sources respon-
sibly for your research, you need to judge each source’s trustworthiness and
quality. This chapter explains how to locate and then evaluate sources.

A source is either primary or secondary. A primary source is original
work such as firsthand reports of experiments, observations, or other research
projects; field research you carry out yourself; and documents like letters,
diaries, novels, poems, short stories, autobiographies, and journals. When you
use a primary source, no one comes between you and the material.

A secondary source reports, describes, comments on, or analyzes some-
one else’s work. This information comes to you secondhand. That is, someone
other than the primary source relays the information, adding a layer between
you and the original material. This does not mean secondary sources are infe-
rior to primary sources. Indeed, scholars and other experts are excellent sec-
ondary sources. However, you need to evaluate secondary sources carefully to
make sure that what’s being relayed to you isn’t distorted or biased in the
process. Turn to 31j for detailed guidelines for evaluating sources.

31b What is a search strategy?
A search strategy is an organized procedure for locating and assembling
information for your research. You find this information in two places: on the
Internet and in the library. Developing a strategy for your search is crucial.
An effective, successful search strategy results from your working systemat-
ically and thoroughly to find material that helps to answer your RESEARCH
QUESTION. A good search strategy helps you structure your research work so
that you don’t mistake activity for productivity.

No two research processes are exactly alike. Be guided by your personal
needs as you adapt the search strategies I explain. Most of all, know that no
search strategy is as tidy as I describe here. Following are three frequently
used designs.

The expert method is useful when you know your specific topic. Begin
by reading articles or books by an expert in the field. Of course, this means

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that you have to know who the experts are, and sometimes that’s difficult.
Talk with people who are generally knowledgeable about your topic, learn
what you can from them, and ask them to refer you to work by experts on
the topic. (For example, if you’re interested in researching artificial intelli-
gence, a computer science instructor may be able to tell you who are the
leading experts on that topic.) Alternatively or in addition, INTERVIEW an
expert, either in person, on the phone, or through e-mail. Turn to 31i for
detailed advice about conducting effective interviews.

The chaining method is useful when you know your general topic and
need to narrow it to a more specific, manageable topic. Start with reference
books and bibliographies from current articles or Web sites. These refer-
ences will lead you to additional sources. Keep up the chain, watching closely
for sources that are mentioned frequently. The frequency is usually evidence
that the sources are probably expert and well respected. As you work, your
general topic usually begins to group and divide itself into subtopics, one of
which might serve as the topic of your research paper. If such division and
grouping doesn’t emerge for you, take a break of a few hours so that you can
reconsider the material with fresh eyes.

The layering method is useful when you need to find your own topic.
You layer information by first consulting general sources and then finding
ones that are more specific. You try to relate the information you gather to
other scholarly sources in the same subject area. Chandra Johnson, the stu-
dent whose research paper appears in 33e, started with the layering method
and soon combined it with chaining.

You, too, may find yourself switching or combining methods. This is per-
fectly acceptable. “Flexibility with focus” is the guiding principle for experi-
enced researchers. Complete your search as soon as possible after you get
the assignment. Discovering early in the process what sources are available
allows you time to find those that are harder to locate; to use interlibrary loan
if an item isn’t available in your library or online; to wait for someone to
return checked-out books you need; or to schedule interviews, arrange vis-
its, or conduct surveys.

31c How do I find sources?
You want to start your search strategy by consulting library and online
sources on your topic. To do this, you need to figure out the keywords (31c.4)
and subject categories that can lead you to useful material.

The library building is where generations of college students have tradi-
tionally gone to find sources. Today, the Internet, which includes the World
Wide Web and additional files, greatly expands the ways you can access infor-
mation. At the library, you find books, periodicals, and lists of sources in cat-
alogs, indexes, and databases. While many college libraries offer home pages
to give you remote access to their holdings via Internet connections, the
library building itself continues to be a vital place for all research. One key

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advantage of going to the library is your chance to consult with librarians.
They trained for their profession by learning how to advise students and other
researchers about using library resources to greatest advantage. Never hesi-
tate to ask questions about how to proceed or where to find a resource.

Catalogs list sources—usually books—that the library owns (see 31d).
Indexes list articles in periodicals; each index covers a specific topic area
(see 31e). Catalogs and indexes exist mainly in electronic format; less com-
monly, some catalogs and indexes are still in print format. Databases always
exist electronically (see 31c.1). They consist of one or more indexes and con-
tain extensive lists of articles, reports, and books. You can access and search
electronic catalogs, indexes, and databases from computers in the library or
by connecting to the library online. You can also subscribe to databases, but
this can be expensive. At most colleges, your tuition pays for access to online
library resources, so take advantage of them.

If you’re accessing a database by connecting to the library online, you
need to use a browser, a software program that gives you access to the Web
and the search engines located there. Netscape Navigator™ and Microsoft
Internet Explorer™ are the two most frequently used browsers.

31c.1 Using databases
Each entry in a database contains bibliographic information, including a title,
author, date of publication, and publisher (in the case of books or reports) or
periodical (in the case of articles). The entry might also provide an abstract,
or summary, of the material. Once you locate an entry that seems promising,
you might need to read a print copy of the source. Some databases provide
the full texts of the articles they cite. Other databases allow you to purchase
full copies of the sources you find. If you’re on a tight budget, try to purchase
only what looks truly useful. You can request materials that are not in your
library through interlibrary loan (31g).

Sources that you identify through scholarly databases are almost always
more reliable and appropriate than sources you find through simply brows-
ing the World Wide Web. Some scholarly research is available from World
Wide Web sites, while others reside at Internet sites not necessarily part of
the Web. The reliability of scholarly databases stems from their origins: Only
experts and professionals who recognize works of merit compile them.

The best way to access a database at your library is to go to your college
library’s Web site, whether you’re online in the library, at home, or in a
dormitory. Each home page of a library shows the resources available
through that Web site. More might be available at the library building itself.
Sections 31d and 31e explain how to use the catalog to find books and peri-
odicals (newspapers, magazines, and journals). Most college libraries sub-
scribe to one or more database services, such as EBSCO, FirstSearch, and
IBIS. Because the college pays for these services, you don’t have to, but
you’ll need an ID or password to use them. Commonly, your student number

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serves as your ID, but check with a librarian to see what’s required at your
college.

E X E R C I S E 3 1 – 1 Working either individually or as part of a group, access
your library’s Web site. You may do this either by going to the library itself or
by connecting to the library online. List all of the types of information avail-
able. In particular, list the indexes and databases you can search and the
subject areas each one covers. Note whether any of the databases have
full-text versions of articles. Note if the library’s Web site has any online
“help” or “search suggestions.”

31c.2 Searching the World Wide Web
The World Wide Web is organized around pages (called Web pages) that are
linked together electronically. A group of pages that an individual or organi-
zation has created and linked together is called a Web site. The main page
in a Web site (called the home page) acts as a table of contents. Although the
Web contains billions of pages, including a great many books and periodical
articles, only a fraction of these sources are available on the Web without
subscribing or paying a fee. Therefore, searching library databases remains
your most important method of finding many scholarly sources. However,
the principles for searching the World Wide Web are much like those for
searching databases (31c.1). You start with a broad subject and narrow it to
arrive at a suitable topic for an academic research paper.

Once you use a browser to get on the Web, you can search for sites by
using a SEARCH ENGINE (31c.3) or by typing an address (called a URL, for
Universal Resource Locator) into the search box.

A L E R T : When you read, write, or type a URL, the Modern Language
Association (MLA) tells you to surround it with angle brackets. For example,
is the URL for our publisher’s Web site
about our books, including this handbook. The brackets separate a URL
from sentence punctuation so that no one mistakes it as part of the URL.
However, never use angle brackets when you type a URL in the locator box
at the top of your computer screen.

31c.3 Using search engines
Search engines are programs designed to hunt the World Wide Web and
Internet files for sources on specific topics that you identify by using key-
words (31c.4). When you use a search engine, you generally can access mate-
rials in one of two ways: through keyword searches (31c.4) and through
subject directories (31c.5).

E X E R C I S E 3 1 – 2 Use at least three different search engines to search online
for the same topic. List the different results for each search engine, and also
note the strengths and weaknesses of each. (Pay attention to usefulness,

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31c FINDING AND EVALUATING SOURCES

ease of use, and so on.) Write a brief report on your findings. You may wish to
try this exercise with a second topic before drawing your conclusions.

31c.4 Using keywords
When searching for sources online or in library databases, keywords,
also called descriptors or identifiers, are your lifeline to success. Keywords
are the main words in a source’s title or the words that the author or editor
has identified as central to that source. Without keywords, you’d have no way
to access sources listed in online or electronic database book catalogs
and periodical indexes. Similarly, to find information on the World Wide
Web or on the Internet, keywords are essential. Because Web search
engines, such as Yahoo, often look for any occurrence of a word in the title
or body of a page, you need to take particular care with keyword searches on
the Web.

When you use keywords to search for Web sources, chances are you’ll
come up with a large or even overwhelming number of sources. Much of
what turns up won’t be relevant to your topic. As a result, you need to figure
out which items on the list might be useful. Whenever possible, narrow your
list of keywords by using BOOLEAN EXPRESSIONS. Your other alternative is to
use a “try and see” approach. Whichever approach you use, always keep a
record of poor and good keywords for your TOPIC in your research log so that
you’ll remember which keywords do and do not work well for you on each
topic. This process might seem tedious at times, but don’t get discouraged.
If you’re stumped, try asking a friend who’s experienced with online searches
or a research librarian for help.

As you become more adept at using keywords, your searches will
become more directed and less time-consuming. The two main ways to
make keyword searches more efficient are using guided searches and using
Boolean expressions.

Using guided searches
Using guided searches means that you search a database or search engine
by answering prompts provided, usually by filling in a form on the screen.
Guided searches often allow you to select a range of dates of publication (for
example, after 2002 or between 1990 and 1995) and to specify only a certain
language (such as English) or a certain format (such as books).

Using Boolean expressions
Using Boolean expressions means that you search a database or search
engine by using keyword combinations that narrow and refine your search. To
combine keywords, you use the words AND, OR, NOT, and NEAR or the
symbols that represent those words. Boolean expressions, generally placed
between keywords, instruct the search engine to list only those Web sites in

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which your keywords appear in certain combinations and to ignore others.
Other commands similarly help you go directly to the sources you most need.

Box 31-1 explains ways to search with keywords more effectively, using
the subject of artificial intelligence as an example. Simply typing the words
intelligence computers emotions would yield pages that include any of these
words—and not necessarily in that . Imagine the staggeringly long list
of pages you’d get for the word computers alone, and then almost triple that

B OX 3 1 – 1 S U M M A R Y

Refining keyword searches

AND or the + (“plus”) symbol: Narrows the focus of your search
because both keywords must be found. If you want to find information on
the role of emotions in artificial intelligence, try the expression artificial
AND intelligence AND emotions. While some search engines, such as
Google.com, don’t require the word AND between terms because they
assume that two or more terms are always connected by AND, most
require it. When in doubt, definitely use AND.
NOT or the � (“minus”) symbol: Narrows a search by excluding texts
containing the specified word or phrase. If you want to eliminate robots
from your search, type artificial AND intelligence AND emotions NOT
robots.
OR: Expands a search’s boundaries by including more than one keyword.
If you want to expand your search to include sources about artificial
intelligence in either computers or robots, try the expression artificial
AND intelligence AND emotions AND computers OR robots. You’ll get
pages mentioning artificial intelligence and emotions only if they mention
computers or robots.
NEAR: Indicates that the keywords may be found close to each other or
on either side of each other. However, depending on the search engine,
NEAR produces hits that are found only in the same sentence or on the
same page. For example, entering intelligence NEAR emotions will yield
only pages in which the words “intelligence” and “emotions” are very close
to one another.
( ): These are parentheses that group two or more expressions together.
For example, (artificial intelligence AND emotions) AND (Turing Test OR
Chinese Room) would find documents about artificial intelligence and
emotions along with either the Turing Test or the Chinese Room Test.
(Chandra Johnson’s research paper in section 33e explains that these are
two tests for judging whether people can regard a computer as
“intelligent.”)
“ ”: These are quotation marks that direct a search engine to match your
exact word on a Web page. For example, a search for “robots that

➞

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think” will find pages that contain the exact phrase robots that think.
However, it won’t return pages with the phrase thinking robots. Also, if
you search for James Joyce without using quotation marks, most engines
will return all pages containing the words James and Joyce anywhere in the
document; however, a search using “James Joyce” brings you closer to
finding Web sites about the Irish writer.
*: The asterisk functions as a wildcard in some search engines. It allows
you to look for sites by listing only the first few letters of a keyword.
This approach, known as a truncated search, is helpful when a term
comes in varying forms. For example, a Yahoo search for cogni* would
turn up directory entries for both cognitive and cognition. You can also
direct the search engine to look for variants of a keyword by using the
wildcard symbol * in place of either the word ending or some of the
letters in the word. For example, a truncated search for wom*n would
return hits for woman and women. Please note that not all search
engines allow wildcarding; Google.com, for example, does not. A few
search engines use specialized symbols such as ? or : instead of the * for
wildcarding.

Refining keyword searches (continued )

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31c FINDING AND EVALUATING SOURCES

number when you include the two other seemingly unrelated words in your
list. In contrast, note the huge amount of weeding out that the Boolean
expressions allow.

To conduct a keyword search, type a word or group of words in
the search box on the opening page of the search engine, and click on the
“Search” or “Enter” button. The engine scans for your word(s) in Web pages,
and then lists sites that contain them. Because the Web has billions of
pages, a search on even a moderately common topic may produce thousands
of hits—sites listed or visited in a search. Not every hit will be what you
are looking for. Very general terms may appear on thousands of Web sites. If
a search engine finds thousands of hits for your keyword, do not give
up. Instead, try more specific keywords, use a guided or “advanced” search
feature, or use the strategies listed in Box 31-1 for refining a keyword search.

E X E R C I S E 3 1 – 3 Use a search engine of your choice to search for sources
on “artificial intelligence.” For each option below, record how many hits
occur.

1. Enter the word artificial.

2. Enter the word intelligence.

3. Enter the phrase artificial AND intelligence.

4. Enter the phrase “artificial intelligence” (in quotation marks).

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How do I find sources? 31c

5. Enter the search phrase “artificial intelligence” computers emotions.

6. Explore adding other words to your search phrase or using Boolean expres-
sions (Box 31-1).

7. Repeat this exercise by searching for another topic that interests you.

31c.5 Using subject directories
Subject directories included on most search engines’ home pages provide a
good alternative to keyword searches. These directories are lists of topics (Edu-
cation, Computing, Entertainment, and so on) or resources and services (Shop-
ping, Travel, and so on), with links to Web sites on those topics and resources.
Most search engines’ home pages have one or more subject directories.

Clicking on a general category within a subject directory will take you to
lists of increasingly specific categories. Eventually, you will get a list of Web
pages on the most specific subtopic you select. These search engines also
allow you to click on a category and enter keywords for a search. For exam-
ple, suppose that you are using yahoo.com to search for information on
artificial intelligence. As the figure above shows, you would first go to
Yahoo’s general category of science. Under science you would find the cate-
gory of computer science, and within computer science you would find a link
to artificial intelligence, a page that lists nineteen additional categories and
dozens of sources.

Several subject directories exist independently of search engines.
Box 31-2 lists the Internet addresses of some directories. One useful direc-
tory is the Librarians’ Index to the Internet (LII). To use the LII, type its
URL, , in the browser’s search box. The first screen you see
is the lii.org home page. You’ll see a number of broad topic areas, and when
you click on one of them, you’ll see a number of subtopics. As you refine
your search, you’ll eventually come to specific pages. One advantage of the
LII is that professional librarians have gathered the pages.

Box 31-3 summarizes the information in this section by providing some
general guidelines for using search engines and directories with keywords.

B OX 3 1 – 2 S U M M A R Y

Addresses for subject directories

Educator’s Reference Desk
(contains ERIC)

Infomine
Internet Public Library
Librarians’ Index to the Internet
Library of Congress
Refdesk.com

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B OX 3 1 – 3 S U M M A R Y

Tips on using search engines and
directories

■ Use keyword searches only when you have a very specific, narrow topic
with unique keywords. If you enter a general topic in most search
engines, you will be overwhelmed with thousands of returns. If this
happens, switch to a subject directory or see if using additional keywords
or Boolean expressions sufficiently restricts the number of hits.

■ Most search engines attempt to search as much of the Web as possible.
But because the World Wide Web is vast and unorganized, different
search engines will give different results for the same search. Try using
more than one search engine, or use a metasearch engine, one that
searches several search engines at once. (Google.com and Dogpile.com
are metasearch engines.)

■ Always check the “Help” screen for the search engine you use. As with
the rest of the Web, search engines add or change features frequently.

■ Specify that the search engine list results by “ranking.” If you do not,
the search results will be returned in random , and the most
important source may be last.

■ If possible, limit the date range. For example, you can often ask to see
only pages that were updated in the past six months or one year.

■ When you find a useful site, go to the toolbar at the top of the screen
and click on “Bookmark” (or “Favorites”) and then click on “Add.”
Doing so allows you to return to a good source easily by opening
“Bookmarks” or “Favorites” and double-clicking on the address.

■ Use the “History” or “Go” function to track the sites you visit, in case
you want to revisit one you previously thought was not helpful. You can
also move a site from “History” to “Bookmark.”

31d FINDING AND EVALUATING SOURCES

31d How do I find books?
A library’s book catalog, which lists its holdings (its entire collection), exists
as a computer database in almost every modern library. You can find a book
by searching by author, by title, by subject, and by KEYWORD. The Library
of Congress in Washington, DC, is the largest library in the world and, as you
might expect, it has the largest catalog.

Suppose a source recommends that you find a book by the author
Antonio Damasio, but you don’t know its title. You can search the catalog for
books by this author. A screen on your library’s computer will have a place

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for you to type “Damasio, Antonio” in a space for “author.” (Usually, you
enter last name, then first name, but check which system your library uses.)
If your library owns any books by Antonio Damasio, the computer will dis-
play their titles and other bibliographic information, such as the library call
number. Then you can use the call number to request the book or to find it
yourself.

Among the books you might find when searching for “Damasio, Antonio”
is The Feeling of What Happens: Body and Emotion in the Making of Con-
sciousness (New York: Harcourt Brace, 1999). Suppose you know that book’s
title, but not its author, and want to see if your library owns a copy. A screen
on your library’s computer will have a place for you to type in the title; in
some systems, you usually do not type words like the or a, so that in this case,
you would type in only “Feeling of What Happens.”

Suppose, however, you don’t know an author’s name or a book title. You
only have a research topic, and you need to find sources. In this case, you
need to search by subject, using the terms listed in the Library of Congress
Subject Headings (LCSH). The LCSH is a multivolume catalog, available as
an electronic database (for a fee) and in book form, and it’s located in the ref-
erence section of every library. The LCSH lists only subject headings, which
are organized from most general to most narrow. Suppose you’re research-
ing the topic of “consciousness.” If you enter that term into a space for sub-
ject searches in your own library’s “Search” screen, The Feeling of What
Happens: Body and Emotion in the Making of Consciousness by Antonio
Damasio will be listed, whether available in your library or through interli-
brary loan.

Finally, you may wish to search by KEYWORD in your library’s holdings.
You could find Damasio’s book using the keywords “feeling,” “body,” “emo-
tion,” “consciousness,” “intelligence,” “mind,” and so on.

An entry in the library’s book catalog contains a great deal of useful infor-
mation: a book’s title, author, publisher, date and place of publication, and
length, along with its location in the library. A full record catalog entry (a
complete set of information about the source rather than a brief listing that
may have only author, title, and call number) lists additional subjects covered
in that book. The list of additional subjects can provide valuable clues for
further searching.

Some libraries allow you to print out this information, send it to your
e-mail account, or download it to a disk. Whether you choose one of these
options or copy the information yourself directly into your WORKING BIBLI-
OGRAPHY, it is crucial to record the call number exactly as it appears, with all
numbers, letters, and decimal points. The call number tells where the book
is located in the library’s stacks (storage shelves).

A call number is especially crucial in a library or special collection with
closed stacks (that is, a library where you fill in a call slip, hand it in at the
call desk, and wait for the book to arrive). Such libraries don’t permit you to
browse the stacks, so you have to rely entirely on the book catalog. If you fill
in the wrong number or an incomplete number, your wait will be in vain.

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31e How do I find periodicals?
Periodicals are magazines and journals published at set intervals during the
year. To use periodicals efficiently, consult indexes to periodicals. These
indexes allow you to search by subject and author. Most exist as online data-
bases, which are updated frequently. Some indexes are published on CD-
ROMs, and a few are published only in print.

Using indexes
Your library’s home page generally provides different ways to access various
indexes. For example, users who select “Show Databases” under “By Sub-
ject” will see an alphabetical list of subject areas, beginning “General …