Sources of Information

1. Primary Sources.

Primary sources are, simply put, firsthand accounts. These bring us as close as possible to the event, the subject, the original idea, or the findings of a scientific study. Some examples of primary sources are:

  • Theses & dissertations
  • Diaries
  • Interviews
  • Letters
  • Speeches
  • Photographs
  • Original works of art & literature

2. Secondary Sources.

A secondary source is anything that comments on, analyzes, or tackles a primary source. The information from the primary source is reviewed, organized, or interpreted, often with the help of other secondary sources. Some examples of secondary sources are:

  • Textbooks
  • Biographies
  • Critical reviews

3. Tertiary Sources.

Tertiary sources are sources that refer to a primary or secondary source. It gives an overview of the topic, but rarely contains original material. Some examples are:

  • Dictionaries
  • Handbooks
  • Tables
  • Encyclopedias

Below are a few examples to help you understand the distinctions between the three types:

Subject Primary Source Secondary Source Tertiary Source
Traffic App
Waze app
Waze User Reviews
Documentary on the effects of sin tax law
Encyclopedia article on tobacco
Harry Potter
Book review
Dictionary of wizarding words
Diary of Martial Law victim
Biography film about a family during Martial Law
List of missing persons or desaparecidos from the Martial Law period