Find Primary, Secondary, and Tertiary Sources in the Sciences

• A primary source describes an original experiment or research that the authors of the article did themselves.
• It usually takes the form of a journal article.
• It provides details on the methods used to conduct the experiment, reports the resulting data, and outlines the authors’ interpretation of the results.
• It usually includes the following sections: Introduction, Methods, Results, Discussion, References.

Look for these key terms:

• Introduction – the section where the authors explain the context and purpose of the research.
• Methods – the section where the authors describe how their experiment was conducted.
• Results – the section where the authors present the data they collected. Tables and graphs often appear in this section.
• Discussion – the section where the authors interpret the results and discuss what they mean.

• A secondary source describes, summarizes, or offers commentary on experiments or research that other people did.
• Summarizes and synthesizes the state of research into a particular topic.
• Can take the form of a journal article, book, or book chapter.
• Can be used to find related primary sources by looking at the reference list.

Look for these key terms:

• Literature review
• Review article
• Systematic review – a type of literature review where authors create a systematic and comprehensive search strategy in order to retrieve all scientific literature that answers a particular research question. The authors will report what this search strategy was in their methods section.
• Meta-analysis – a statistical analysis, often performed as part of a systematic review, that combines the results of multiple research studies.

• A source that broadly summarizes what is known on a scientific topic, or that collects facts or data.
• Usually takes the form of an encyclopedia, handbook, field guide, or textbook.

Look for these key terms:

• Encyclopedia – a book or set of books consisting of entries, often arranged alphabetically, on topics of general knowledge or a specific discipline.
• Handbook – a book that contains facts, data, or instructions, and that is designed for quick reference.
• Field guide – a type of handbook that is meant for quick reference while working in the field.
• Textbook – a book written to teach the reader about a topic. Usually only contains information on which there is a broad scientific consensus.