Evaluating Sources

Once you have gathered possible sources, look at them critically. Some sources will stand out as more relevant and reliable. By evaluating all your sources, you can best decide which ones to use and how to use them. In learning to evaluate sources, we will cover the following:

  • Who - the author
  • What - the sponsoring organization
  • When - the date
  • Why - the purpose
  • Bias or slant - evaluating the author, sponsor and purpose
  • Overall - relevance, reliability and completeness of content

With printed material, you will be looking for an author, publisher and copyright date. With online information, you will be looking for an author and sponsor, such as a government department, company or educational institution. Websites, in particular, can be tricky to evaluate.

Who (authorship)

The presence of an author can be a clue to the intent and validity of the work. Authors are often listed on the title page, in the preface, or at the beginning of an article. The preface, at the beginning of a book, often explains why the book was written. The preface sometimes provides the selection criteria for published articles.

Websites do not have a standard format for displaying authorship. The author's name may be listed either at the top or bottom of the article or page. If you happen to land in the middle of a website, you might have to do some detective work. Try using the "previous" or "next page" button. The author may be listed before or after the page you're on. Another approach is to find the homepage to help identify who created the page. If you can't find the homepage, try erasing parts (from the right) of the URL until you get to the domain address.

Once you find the author(s), ask the following questions to find out if the author knows the subject:

  • Does the author have specific qualifications, like an academic degree or affiliation with a professional organization or institution?
  • Does the author work in the field s/he is writing about?
  • Is the content of the material related to the author's qualifications?

What (sponsorship)

Not all your sources will have an author listed. On printed material, you might find editors and a publisher. Again, this information is usually listed at the beginning of a book or article. On electronic material, if there is no author listed, you need to find the work's sponsor. If the source is a website, try looking in the "About Us" section. Is the publisher or sponsor one you recognize? If so, what is their reputation?

If you can't find a sponsor, you can always glean some information from the URL itself. The last part of the domain name will reveal:

  • .com - a commercial entity
  • .edu - an educational institution
  • .org - a non-profit organization
  • .gov - a government agency
  • .mil - a military organization
  • .net - a computer network or technical group
  • .us, .uk., etc. - country designations
  • .biz, .info, etc - new designations for business, etc.
 
hand with finger pointing
Authorship and Sponsorship is Important
Different companies or organization can present radically different points of view. For example, articles about cigarette smoking by the American Cancer Society will contrast sharply from those by the Phillip Morris Company.
 

When- how current is the information?

How critical is the creation date to your research? There are times when current information is vital to your research. For example, up-to-date information would be essential in researching the following:

  • New medical techniques
  • Latest statistics
  • Company financial statements
  • Current address for a lost relative

Of course, if you were researching a historical event, you would want historically accurate data. For example, if you were researching the Civil War, you might want eyewitness accounts from the 1860's; however, the publishing date may not be relevant.

If the date of the source is important, here are some questions to help you along:

For printed material -
  • When was the article/book written?
  • What is the copyright?
  • When was the latest edition printed?
For electronic materials
  • When was the site created?
  • When was the site last updated?
 
hand with finger pointing
Remember - the date may not matter for some topics.
For example, if you are researching a famous person, your source material dates are less important.
 

Why- determine the purpose

It is always a good idea to consider the author's motivation. The book or Web page may have been created to support a narrow viewpoint or opinion. Is it identified as such? For example, reports from lumber companies may differ sharply from those of environmental organizations in their analysis of proposed logging measures. Knowing the author's motivation or purpose will help you discern whether he or she has a particular bias.

Here are some questions that might help in the process:

  • Is it someone's hobby or personal opinion - not related to his or her profession?
  • Is it a report on a topic that the author is an expert in?
  • Is it selling a product or point of view?
  • Is there documentation to support the opinions or facts given?
  • Are the facts well balanced?
  • Can you identify where the information came from?

Bias or slant

Once you have determined the author, sponsor and purpose of the article, book etc., you can get a better sense of possible bias. Things to look for:

  • Is the author affiliated with a particular company or organization that has a stake in the issue being discussed?
  • Is the information balanced?
  • Is the tone or language inflammatory?
 
footnotes
When in doubt about a source:
Don't use it.
 
 

Overall- Analyze the content

You will have to analyze each of your sources.

  • Decide if each source is relevant to your topic
  • Decide if the information is reliable.
  • Determine how well your sources cover the topic you're covering.

Relevance

Here you will need to determine if the information you have found is useful and relevant to your topic.

  • Does the information match your needs?
  • Does it contain supporting facts and statistics?
  • Is it consistent with other information you have found?
  • Is the language appropriate for your needs? Reports can sometimes be too technical, or too elementary, to use.

No matter how fascinating a source, don't use it if it doesn't fit in well with your topic.

Reliability

You'll need to determine how accurate and reliable each source is. You have already made some progress in answering this question in determining the author, sponsor, and publication date of the material. However, you now need to weigh the content of your sources against each other to reach a final decision. Ask yourself the following questions:

  • Is the information consistent from one source to another?
  • Was the information supported by other research or independent sources?
  • In what areas do your sources disagree or contradict each other?

Look closely at any contradictory information. Some detective work may be needed to determine the best source on particular points. Here are some questions to help you decide which sources are the most reliable:

  • Is it well written? Does it contain good grammar and spelling? Documents that are poorly written should be scrutinized.
  • Does one author/publisher/sponsor carry more weight than another?
  • Which sources have the best evidence?
  • Which sources have the most convincing arguments?

Completeness

Does the information you have collected fully cover your topic? Are there any holes or gaps? If you find you do have to go back and fill in missing information, you can probably work with the sources you already have to get the missing pieces. Check your sources for a list of citations and a bibliography. These should lead to other related materials. Another strategy is to refine your previous searches or expand into related subjects.

 

Evaluation Example

To better see how these evaluation guidelines actually work, let's use them on our sources on male breast cancer. The following sources were found through our previous searches:

 
#Search MethodSourceTypeReference and/or Description
1MelvylBookLove, Susan M.. Breast book. Dr. Susan Love's breast book, Susan M. Love, with Karen Lindsey; illustrations by Marcia Williams. 2nd ed., fully rev. Reading, Mass.: Addison-Wesley, c1995. xxviii, 627 p. : ill. ; 24 cm
2PubMedJournal ArticlePollan M, Gustavsson P, Floderus B. Breast cancer, occupation, and exposure to electromagnetic fields among Swedish men.Am J Ind Med. 2001 Mar;39(3):276-85.
3lii.orgWebsite Sponsored by American Cancer SocietyCancer Statistics
http://www3.cancer.org/eprise/main/docroot/STT/stt_0
This American Cancer Society site offers information on the causes, treatment and prevention, and financial costs of all types of cancer and statistics for fourteen specific cancers, including cancer in children, leukemia, breast, lung, skin, and colon/rectum cancer. Included are additional sections on Cancer in Minorities, Prostate Cancer, Tobacco Use, Nutrition and Diet, and Environmental Cancer Risks. There are also nineteen charts and graphs representing different statistical information, e.g., Estimated New Cases of Cancer, by State; Age-Adjusted Cancer Death Rates for Males and Females by Site; 20-Year Trends in Cancer Death Rates, etc.
Subject: Cancer -- Statistics
Created by: de on Aug. 22, 1999 - last modified by wh on Dec. 30, 2000
4altavista.com
google.com
alltheWeb.com		Website Sponsored by an individualhttp://interact.withus.com/interact/mbc/
This site is for anyone dealing with male breast cancer whether they be a man suffering from this disease, his doctor, other doctors interested in the disease, and researchers studying MBC.
 

Using our evaluation criteria, we can summarize our sources as follows:

 
 AuthorPublisher/ SponsorDatePurposeBiasRelevanceReliability
Source 1ExpertProfessional1995Public information MedicalBroad backgroundHigh
Source 2ExpertProfessional2001Medical researchResearchSpecific causesHigh
Source 3ExpertNon-profit2000Public informationAnti-cancerStatisticsHigh
Source 4IndividualSelf1995-98Public informationSelf-helpPersonal case???
 

Authors

Based on our evaluation criteria summary, sources 1, 2, and 3 were written or compiled by experts in their fields. Source 4 was written/compiled by an interested party (a male patient with breast cancer). Even though this author is not an expert, his material may still be useful. He will be speaking from personal experience of the disease and can offer a valuable perspective.

Publisher/Sponsor

Reputable professional publishers printed sources 1 and 2. The American Cancer Society, a non-profit agency, compiled source 3. Considering the reputation of these three sources, the information should be of professional quality. Source 4 was self-published on the Web by an individual without a sponsor. While this situation may stir some doubts, let's continue to examine this source from different angles before accepting or rejecting it.

Dates

Since we are researching a medical topic, we are primarily interested in current information. Sources 2 and 3 easily fulfill this requirement. However, Sources 1 and 4 are more questionable. Source 1 has already undergone several editions, so we should look for a newest edition. Since Source 4 provides more of a personal perspective, the date is less important.

Purpose

It appears that all our sources were published for use by the public and/or for medical research. Even though a private individual published Source 4, his purpose appears to be to help other- male breast cancer patients. Thus, all the sources appear to be relevant and reliable.

Bias

A quick look through the particular biases of our sources doesn't raise any problems for our topic.

Relevance

Source 1 provides a broad discussion of breast disease, which would be useful in an introduction or topic overview. Source 2 presents medical research on possible causes, which is definitely relevant to our topic. The statistics provided in source 3 would be useful in an introduction or topic overview. The personal viewpoint provided by source 4 is also useful.

Reliability

Sources 1, 2, and 3 appear to be highly reliable. The reliability of source 4 takes some detective work. The quality of the information appears to be high. It correlates well with other information on male breast cancer. Consequently, even though a private individual published the information on the Web, it appears to be reliable. The only caveat is that some of the information is dated.

Completeness

As a last step, we need to take an overall look at our sources. We have good background information from Sources 1 and 3. We also have some information on possible causes from Source 2. We have personal patient experience from Source 4.

So what's missing? We could use more on possible causes. Also, we don't have any information on current treatments. So it's back to the library and the keyboards to round out our topic.

 
 

Online Resources: