History (UNH Manchester): Types of Sources

In general, there are three types of resources or sources of information: primary, secondary, and tertiary.  It is important to understand these types and to know what type is appropriate for your coursework prior to searching for information.

1. Primary sources are original materials on which other research is based, including:
   • original written works – poems, diaries, court records, interviews, surveys, polls, statistical information, and original research/fieldwork; and
   • original research published in scholarly/academic journals.
2. Secondary sources are those that describe or analyze primary sources, including:
   • reference materials – dictionaries, encyclopedias, textbooks, and
   • books and articles that interpret, review, or sythesize original research/fieldwork.
3. Tertiary sources are those used to organize and locate secondary and primary sources.
   • Indexes – provide citations that fully identify a work with information such as author, titles of a book, article, and/or journal, publisher and publication date, volume and issue number and page numbers.
   • Abstracts – summarize the primary or secondary sources,
   • Databases – are online indexes that usually include abstracts for each primary or secondary resource, and may also include a digital copy of the resource.