.Information Literacy in the Health Sciences

The following definitions refer to published or recorded information, where the information is put in a (reasonably) permanent form.

Primary sources, secondary sources, and tertiary sources as definitions deal with
a phenomenon, idea, or research study and
the relationship of the person reporting about it
to that phenomenon, idea, or research study.

The concept of a "primary source" is important in the understanding of information and research.

• A primary source is a source that provides firsthand information to the reader/audience.
• A secondary source is a source which provides secondhand information to the reader/audience.
• A tertiary source is a source that provides thirdhand information to the reader/audience.

So what does this mean?
The Merriam Webster Dictionary provides the following definitions:

• firsthand (adjective) : obtained by, coming from, or being direct personal observation or experience |a firsthand account of the war| … had a firsthand view of the turmoil that wracked the region. —William W. Finan, Jr.| 
• secondhand (adjective) 1a: received from or through an intermediary : borrowed 1b: derivative secondhand ideas 2a: acquired after being used by another : not new |secondhand books| 2b: dealing in secondhand merchandise |a secondhand bookstore| 
  
• thirdhand (adjective) 1: received from or through two intermediaries |thirdhand information| 2a: acquired after being used by two previous owners 2b: dealing in thirdhand merchandise

Notice that the distinguishing feature is whether the author(s) of the source experienced or saw the thing themselves (firsthand) or whether others told them about it (secondhand or thirdhand). 

This is important with information. It can be important whether the person(s) providing the information experienced it themself or whether they are telling what others told them. It might affect the credibility of the information.

The definition of "primary source" can vary across disciplines. In the discipline of history, a primary source could be a document or object from the time period or historical event under study. In the health sciences, experts are usually referring to documentation of research studies authored by the people who actually did the study. Or scientific experts may refer to the data collected about the phenomenon under study.

Secondary sources and tertiary sources are authored by people who did not experience the thing themselves but learned about it from other sources.

This might make more sense when you look at examples.

If the wife of the president writes a book about herself and also about her husband the president, 

1. It is a primary source, if the student is interested in the material about the wife of the president.
2. It is a secondary source, if the student is interested in the material about her husband the president.
3. It is a primary source, if the student is interested in the event of the presidency of that president and and experiences of the people involved with that president and the role of the presidency.

EXAMPLES

The following definitions refer to published, available information where the information is put in a (reasonably) permanent form.

A Primary Source is an original source that first reported a phenomenon, idea, or research study as reported by the person(s) who developed the idea or who did the research or who was present. 
 

The key feature of a primary source is that it is a firsthand account. OR it is original evidence of the phenomenon itself.

Primary sources may include newspaper articles, research reports, trade journal articles, conference proceedings, dissertations, Web sites, novels, poems, plays, speeches, interviews, letters, case studies, test data, findings from surveys, archaeological drawings, experiments, films, drawings, designs, paintings, music, sculptures, etc. IF the source is the *original* source of information as told by a person who did it or developed it or observed it or experienced it. 

Primary sources can vary by discipline. But a primary source is always an firsthand source by someone who was there at that place and time.

In science and medicine, a primary source is an original research study as written/told by the original researchers. Therefore, a primary source is a report of a research study by the researchers who did the research. Someone who watched the experiment but did not participate usually does not count. Researchers most often publish their research projects in scholarly peer-reviewed journal articles of their discipline. But some original research studies may be shared via other sources, such as government reports or conference presentations.

Secondary Sources are resources that analyze, describe, comment on, and synthesize the primary or original source. So they are sources that are about someone else's original work, observations, writings, etc. These include review articles, newspaper articles, books or other sources not authored by the author of the original source.

Some professors and scholars include in the definition of secondary sources textbooks and reference books, such as encyclopedias and dictionaries. (See the definition of Tertiary Sources below.)

There is some disagreement among experts regarding the distinction between secondary sources and tertiary sources. But because you may encounter the phrase "tertiary source," it helps to know what is meant.

Tertiary sources are resources written about the secondary literature. In other words, literature which explains, teaches you how to use, and leads you through the vast array of primary and secondary scientific literature. Examples may include textbooks, monographs, bibliographies, encyclopedias and reference books of all kinds which provide a summary of accepted knowledge about a topic or subject area in broad outline. Librarians disagree on the precision of this definition and some do not use the term at all, preferring categories of only primary and secondary sources. But when they do use the phrase "tertiary source," this is what they mean.

What is "gray literature?" (Or the British spelling "grey.") Gray literature is information that has not been formally published and, therefore, is unavailable or hard to find. A good analogy is “as a shadow which has not yet acquired substance”. Also called “fugitive literature,” it usually refers to knowledge that is out in the world but has not yet been formally written down and distributed. For example, researchers may discuss a research study with colleagues and references may turn up in that person's paper but the original study itself is not available in a permanent form. Sometimes the information in gray literature never becomes available to you! For example, if a pharmaceutical company is researching a new drug and doesn’t distribute the information outside of its own employees because it doesn’t want to help the competition. Or a researcher collects data but never bothers to publish their research findings for some reason.

Gray literature publications include theses, conference proceedings, technical specifications and standards, non-commercial translations, bibliographies, technical and commercial documentation,  government documents, and reports (pre-prints, preliminary progress and advanced reports, technical reports, statistical reports, memoranda, state-of-the art reports, market research reports, etc.). (Alberani, 1990)

The Grey Literature Report of the New York Academy of Medicine notified subscribers of gray literature publications in health services research and selected public health topics from 1999-2016. You can search their Grey Literature Collection as if you were searching a library catalog. Records of results of interest would have to be retrieved like any other book. It also listed organizations that publish grey literature.