When researching a topic, you will need to explore a variety of information sources to discover more about a topic, answer your research question, and meet the other information needs of your research project.

This section about categorizing sources will increase your sophistication about them and save you time in the long run because you’ll understand the “big picture”. That big picture will be useful as you plan your own sources for a specific research project, which we’ll help you with in the next section Sources and Information Needs.

You’ll usually have a lot of sources available to meet the information needs of your projects. In today’s complex information landscape, just about anything that contains information can be considered a potential source.

Here are a few examples:

• Books and encyclopedias
• Websites, web pages, and blogs
• Magazine, journal, and newspaper articles
• Research reports and conference papers
• Field notes and diaries
• Photographs, paintings, cartoons, and other art works
• TV and radio programs, podcasts, movies, and videos
• Illuminated manuscripts and artifacts
• Bones, minerals, and fossils
• Preserved tissues and organs
• Architectural plans and maps
• Pamphlets and government documents
• Music scores and recorded performances
• Dance notation and theater set models

With so many sources available, the question usually is not whether sources exist for your project but which ones will best meet your information needs.

Being able to categorize a source helps you understand the kind of information it contains, which is a big clue to (1) whether might meet one or more of your information needs and (2) where to look for it and similar sources.

A source can be categorized by:

• Whether it contains quantitative or qualitative information or both
• Whether the source is objective (factual) or persuasive (opinion) and may be biased
• Whether the source is a scholarly, professional or popular publication
• Whether the material is a primary, secondary or tertiary source
• What format the source is in

As you may already be able to tell, sources can be in more than one category at the same time because the categories are not mutually exclusive.

In historical research the most commonly used categories are primary, secondary, tertiary and scholarly or popular for secondary/tertiary sources.