How to Evaluate any Source
Beyond finding out about the author and considering the basic citation information, it is very important to do more thorough critical thinking about any source you use in your research. For books, scan the Table of Contents and the Index to get a broad overview of the material covered. Note whether bibliographies are included. Read the chapters that specifically address your topic.
A very useful method of organizing your ideas about a source is to write a critical annotation of that source. An annotation is similar to an abstract, which is a brief summary of an article or book. While an abstract usually just provides a summary of what is included in a source, an annotation generally includes a critical evaluation of a source. Click here to see an example of an annotated bibliography.
To try to systematize the process of writing critical annotations, librarians at the McIntyre Library, University of Wisconsin-Eau Claire developed a series of questions to ask about any book, article or other publication that is to be critiqued. The questions (slightly revised) are listed below, followed by suggestions for how to answer each of the questions in order to evaluate different types of sources and to develop your own annotations.
These questions should be used as general guidelines in the process of analyzing a book, article or other work. It will not always be possible to answer all of these questions about a work. If the subject of the work is relatively new to you, it will be more difficult to answer some of the questions; but the process of trying to answer the questions should help you become more familiar with the subject. As you gain more background on the subject, you will increase your ability to critically evaluate writing on the the subject. Whether or not you can answer all of the questions, however, simply taking the time to think about each question for each book or article that you use in your research can be very helpful in developing your critical thinking skills in the research process.
- What is the author's purpose for writing the work?
Gaining some information about an author's background can often shed some light on the author's motivation for writing a work. Although sometimes an author may purposely hide his reasons for writing something, usually authors will openly state their purpose. This will generally be presented within the first several paragraphs of an article. A book's preface or introduction, whether written by the author or not, will usually provide significant information not only on the book's purpose, but also on the author's background, point-of-view and how the book relates to similar works.
- Who is the intended audience? Is it intended for the general public, scholars, policy
makers, teachers, professionals, etc.? Is this reflected in the author's style of
writing or presentation? How so?
The intended audience of a work is rarely stated explicitly, but it can usually be inferred from various clues. The purpose of a work may suggest a particular audience. Other evidence may be found in the writing style, use of jargon and footnotes. Use of a specialized vocabulary, such as medical or legal jargon, for example, would imply that the work is intended for medical or legal practitioners. Information about the periodical in which an article is published will provide a good indication of the audience for a specific article. As mentioned above, Magazines for Libraries (Ready Reference section: Z 6941 .K21 1995) is an excellent reference tool for finding basic descriptions of periodicals.
- Does the author have a bias or make assumptions upon which the rationale of the work
rests? Is the information covered fact, opinion, or propaganda?
An author's point-of-view or bias may be his political orientation or a literary, artistic, scientific or other academic school of thought. Familiarity with the subject of a work is especially helpful in detecting an author's viewpoint. Background information about the author will often provide some evidence of his political perspective or school of thought. Understanding the author's purpose in writing the work will commonly suggest his bias on the subject. The perspective of an author may not always be detectable in his writing, but if it is possible to determine the point-of-view of a particular work, that information can be very helpful in understanding the work as a whole. Particular biases or perspectives should not be thought of as correct or incorrect, but as an important piece of data to be considered when analyzing the work.
It is not always easy to separate fact from opinion. Facts can usually be verified; opinions, though they may be based on factual information, evolve from the interpretation of facts. Skilled writers can make you think their interpretations are facts. Assumptions should be reasonable. Note errors or omissions.
- What method of obtaining data or conducting research was employed by the author? Is
the material primary or secondary in nature? Is the work based personal opinion or
experience, interviews, library research, questionnaires, laboratory experiments,
case studies, etc.? Does the information appear to be valid and well-researched, or
is it questionable and unsupported by evidence?
The method of obtaining data or conducting research for a work will vary according to the type of work and the discipline. More popularly-oriented articles or books may simply be based on an author's personal opinion, first-hand experiences or on a limited amount of interviewing or library research. More academic works generally involve more extensive research. Depending on the discipline, data-collection techniques may include bibliographic research, laboratory experiments, textual analysis, surveys, empirical observation, etc. Most works use various combinations of techniques and the methods used are commonly specifically stated in the work.
Primary sources are the raw material of the research process. Secondary sources are based on primary sources. For example, if you were researching John F. Kennedy's role in the United States' involvement in Vietnam, Kennedy's own writings would be one of many primary sources available on this topic. Others might include relevant government documents and contemporary newspaper articles. Scholars use this primary material to help generate historical interpretations--a secondary source. Books, encyclopedia articles, and scholarly journal articles about Kennedy's role are considered secondary sources. Choose both primary and secondary sources when you have the opportunity.
- What are the author's conclusions?
The conclusions of a particular work are usually relatively easy to find in a work. In articles, in particular, sentences or paragraphs near the end of the piece will often begin, "In conclusion," "In summary," or with some other explicit wording. Books often include a concluding chapter. Although the conclusions of a work are very important to consider, they should be thought of as one element in the overall analysis of a work.
- Does the author satisfactorily justify the conclusions? Why or why not?
Determining how well an author justifies his conclusions can be quite difficult for those not very familiar with the subject of a work. For example, those more familiar with the subject area are more likely to recognize significant information that was not included in a work. In considering how well a work's conclusions are justified, it is usually helpful to think about the author's purpose, point-of-view, intended audience and methods of collecting data at the same time as analyzing the conclusions. The general question to ask is: Do the facts in the work fully support the conclusions? Some specific questions to consider about the work are: "Is it internally consistent and does the logic follow? Did the bias determine the method of data collection or the interpretation of the data collected? Was the method of data collection the best one for the original purpose?"
- How does this work compare with similar works? Is it in tune with, or in opposition
to, conventional wisdom, established scholarship, professional practice, government
policy, etc.? Are there specific writings, schools of thoughts, philosophies, etc.
with which this work agrees or disagrees?
Although knowledge of the discipline of a work is very helpful in determining how that work relates to the subject matter as a whole, authors often explicitly mention other writers with whom they agree or disagree. In addition, footnotes and bibliographies provide specific references which, in turn, can be researched for comparisons to the original work.
- Are there significant attachments or appendixes, such as charts, maps, bibliographies,
photos, documents, tests or questionnaires? If not, should there be?
Attachments, such as charts, maps, survey instruments, appendices or bibliographies, can provide important clarification or enhancement to the basic text of a work. Often, when specific data--such as survey responses or statistical data--is referred to in a work, the actual data may be included or summarized in an appendix. At the same time, the lack of certain supporting attachments may suggest a definite limitation in a work. Such supporting appendices should not be overlooked when evaluating a work.