Source Evaluation - Core Principles

Core Principles

The following principles are cited from two Scandinavian textbooks on source criticism, Olden-Jørgensen (1998) and Thurén (1997) written by historians:

• Human sources may be relics (e.g. a fingerprint) or narratives (e.g. a statement or a letter). Relics are more credible sources than narratives.
• A given source may be forged or corrupted; strong indications of the originality of the source increases its reliability.
• The closer a source is to the event which it purports to describe, the more one can trust it to give an accurate description of what really happened
• A primary source is more reliable than a secondary source, which in turn is more reliable than a tertiary source and so on.
• If a number of independent sources contain the same message, the credibility of the message is strongly increased.
• The tendency of a source is its motivation for providing some kind of bias. Tendencies should be minimized or supplemented with opposite motivations.
• If it can be demonstrated that the witness (or source) has no direct interest in creating bias, the credibility of the message is increased.

We may add the following principles:

• Knowledge of source criticism cannot substitute subject knowledge:

"Because each source teaches you more and more about your subject, you will be able to judge with ever-increasing precision the usefulness and value of any prospective source. In other words, the more you know about the subject, the more precisely you can identify what you must still find out". (Bazerman, 1995, p. 304).

• The reliability of a given source is relative to the questions put to it.

"The empirical case study showed that most people find it difficult to assess questions of cognitive authority and media credibility in a general sense, for example, by comparing the overall credibility of newspapers and the Internet. Thus these assessments tend to be situationally sensitive. Newspapers, television and the Internet were frequently used as sources of orienting information, but their credibility varied depending on the actual topic at hand" (Savolainen, 2007).

The following questions are often good ones to ask about any source according to the American Library Association (1994) and Engeldinger (1988):

1. How was the source located?
2. What type of source is it?
3. Who is the author and what are the qualifications of the author in regard to the topic that is discussed?
4. When was the information published?
5. In which country was it published?
6. What is the reputation of the publisher?
7. Does the source show a particular cultural or political bias?

For literary sources we might add complementing criteria:

1. Does the source contain a bibliography?
2. Has the material been reviewed by a group of peers, or has it been edited?
3. How does the article/book compare with similar articles/books?