LIFE 120/121 Labs: Primary Sources

Sources are considered Primary, Secondary, or Tertiary, depending on the originality of the information and how close they are to the source of information.  Definitions of what is considered primary or secondary literature differ across disciplines.

Primary sources are reports of original research information and experimentation.  A Primary source:

• documents original research experiments or studies.
• is written by the researchers who conducted the research.
• reports the methodologies, data, results, and conclusions from scientific experiments or research studies.

Types of Primary sources: 
Article in scholarly journals or periodicals - the main type of publication in which scientific research is reported, may be published by learned societies or by commercial publishers.
Conference paper - May be not published, published in abstract form, published in advance as a preprint, or published in the conference proceedings, in book form or as part of a special issue of a journal.
Preprint - openly published before peer review and publication in a scholarly journal.
Research reports - individual publications reporting research.
Thesis/Dissertation - written research paper, based on original research,  that describes the masters or doctoral graduate student research. Contains an extensive bibliography of related primary literature.
Patents - provides research information on new products or processes.

Secondary sources contain commentary or discussion about primary source material.  A scholarly secondary source:

• does NOT report new research or new data
• refers to information from previously published primary source material
• summarizes, restates, compares, evaluates, analyzes, interprets, reviews or comments on information reported in the primary literature.
• cites the primary source, with the citation to the original source found in the bibliography.

Examples of Secondary Sources:
Literature/Article Reviews - Articles that summarize the current literature on a topic, and may be labeled as review, literature review, systematic review, or meta-analyses.  
Review Journals - Articles in journals which have titles like Biological Reviews, Annual Review of... , Advances in... , or Current Opinion in...  
Data compilations - Articles, monographs or databases that consolidate research data drawn from primary sources.

Tertiary sources rarely contain original material. A Tertiary source:

• Compiles, indexes and collects information from primary or secondary sources.
• Repackages  information  from primary & secondary sources 
• provides an overview or compiles data on a particular topic
• identifies, organizes  and provides access to primary and secondary sources

Examples of Tertiary Sources:
Textbooks, Handbooks, Encyclopedias, Databases/article indexes

Primary source articles report on original scientific research.

• Was it written by  the original researchers?
• Does it document the research methodology, data/findings and conclusions?
• Is there a Methods, Results and Discussion section (the standard structure of a scientific article)?

The best place to look for primary, scientific articles is by searching in the journal databases provided by the library. These databases contain millions of articles; most of them are primary articles from scholarly journals.

Many of these databases allow you to limit your search results to only articles or peer-reviewed journals; even so, you still need to look at the content and structure of the article to determine if it is scholarly and contains original research.

Some database to consider:

Find more databases: