Primary and Secondary Sources for Science

Primary and Secondary Sources for Science
In the Sciences, primary sources are documents that provide full description of the original research. For
example, a primary source would be a journal article where scientists describe their research on the
human immune system. A secondary source would be an article commenting or analyzing the scientists'
research on the human immune system
What Are Primary Sources?
A primary source is an original object or document -- the raw material or first-hand information. Primary
sources include historical and legal documents, eyewitness accounts, results of experiments, statistical
data, pieces of creative writing, and art objects. In the natural and social sciences, primary sources are
often empirical studies -- research where an experiment was done or a direct observation was made. The
results of empirical studies are typically found in scholarly articles or papers delivered at conferences, so
those articles and papers that present the original results are considered primary sources.
Primary articles, also called original research articles, are the original sources for information. Original
sources are critical for documenting the validity of information for research projects. The most reliable
primary sources of information are likely to be articles in journals that focus on specific areas of research.
Primary articles often appear in what are called scholarly or peer-reviewed journals. Secondary articles
also appear in such journals, but they serve to review the primary articles of other researchers. Exception:
Some 'books' are collections of original research reports from a conference or symposium on some topic. Any
article in a book format that satisfies the criteria for primary sources described below would be a primary
To confirm that an article is a primary research article, ask the following questions:
Does this article give the materials and methods for conducting the research?
o If it says little about what another researcher must know to repeat the experiment, it is
not a valid primary article. Stop right here and evaluate this article as a secondary source
of information.
o If it mentions the number of subjects and their race and gender, but little if any detail
about the actual experimental conditions, it still is not a valid primary article.
Does this article give every detail of the results for experiments that the authors have conducted
o If it describes only what others have done, it is not a primary research article.
o If it gives only a summary of results (meaning few details) and no details for statistical or
some other form of analysis, it is not a valid primary article.
Does the article give complete references to support the claims within?
o A "complete reference" is an accurate description for a source of information.
o Complete references enable readers to find and verify the author's sources.
o Some popular articles also cite complete references, but primary articles always do.
Example of a complete reference:
Oliver, T.A., and Shapiro, F. (1993) Self-efficacy and computers. J. Computer-Based
Instruction 20(3):81-85.
Notice the authors, year of publication, journal title (italics), and volume (issue), and page
Has the article gone through peer review?
A valid primary article is one that has been approved by peers (fellow researchers in the
same field, usually anonymous to the authors of the article).
An article that satisfies the conditions above is likely to have been peer-reviewed.
Secondary Sources
Secondary sources are review articles and books. Reporters, technical writers, or even researchers often
write them. They summarize one to several studies, usually on the same topic.
Examples of secondary sources of information are books, popular magazines, newspaper articles,
newsletters, and letters to the editor (even if in peer-reviewed journals).
Even review articles in peer-reviewed journals, written by researchers, are secondary sources that
happen to be in the same journals as primary research articles. (Review articles organize and
evaluate published research on specific topics, listing complete citations for each research paper
Articles that quote researchers from oral interviews are secondary sources. The researchers being
quoted publish their written work in primary research articles.
Articles that do not satisfy the criteria for primary sources most likely are secondary.
Secondary sources may or may not cite complete references for the information within.
o A "complete reference" is an accurate description for any source of information, so that a
reader can locate this source.
o Review articles in scholarly journals (all of which contain primary articles) always cite
complete references.
o Popular articles may cite complete references, but often include only a few clues as to
their sources or none at all.
o Books often cite references.
Exception: Some 'books' are collections of original research reports from a conference or symposium on some
topic. Any article in a book format that satisfies the criteria for primary sources would be a primary article.
Primary Source
Secondary Source
Original materials that have not been filtered
through interpretation or evaluation by a
second party.
Sources that contain
commentary on or a
discussion about a primary
Primary sources tend to come first in the
publication cycle.
Secondary sources tend to
come second in the
publication cycle.
FORMATS--depends on
the kind of analysis
being conducted.
Conference papers, dissertations, interviews,
laboratory notebooks, patents, a study
reported in a journal article, a survey reported
in a journal article, and technical reports.
Review articles, magazine
articles, and books
Article in scholarly journal reporting research
and methodology.
Articles analyzing and
commenting on the results
of original research; books
doing the same
Example: Scientists
studying Genetically
Modified Foods.
Primary Source
Conference Papers
Lab Notebooks
Studies or Surveys
Technical Reports
Secondary Source
Criticism and Interpretation
Government Policy
Guide to Literature
Law and Legislation
Moral and Ethical Aspects
Political Aspects
Public Opinion
Social Policy
The Evolution of Scientific Information (from Encyclopedia of Library and Information Science, vol. 26).
Instructional guide created by Robert Hyde in Fall 2000. Copyright © 1999, 2000 Robert Hyde.