Finding Effective Types of Sources

Instructor: Christopher Sailus

Chris has an M.A. in history and taught university and high school history.

In this lesson we discuss the different types of effective sources, the qualities effective sources have, and a few methods which can help you find effective sources.


Information has to come from somewhere; it has to have a source. Just read any newspaper or online article, and you are likely to see something like 'according to sources…' or 'sources close to the issue say…' Indeed, sources are very important. But what is a source? How do you find them?

In this lesson we will explore these questions and give a rough guide in how to go about finding sources.


There are two basic types of effective sources: primary sources and secondary sources.

Primary Sources

A primary source is any person, document, or other source that has or represents first-hand knowledge of the event or issue being investigated. These include a wide range of possible sources, from people, to documents, to video footage. For example, primary sources for an investigation of crop yields in the 19th century could include a county ledger of crop sales, The Department of Agriculture's release of agricultural numbers, or the diary of a farmer from the period. Anything that can speak about the issue as the result of direct experience is considered a primary source.

This is not just the case for historical questions either. Journalists, for example, are constantly on the hunt for primary sources. When writing about a battle, for instance, a journalist likes to talk to civilians or soldiers who were directly involved in the fighting, or get their hands on an official army report. All of these are primary sources; they have direct knowledge of the event itself.

Primary sources do not have to be just people or papers; they can also be objects that illustrate something about the event. In our two examples above, a farm implement from the period, or a bullet or shell expended in the fighting, would both be considered primary sources.

Secondary Sources

Secondary sources are any source of information about the event which is one step removed from the actual event. Continuing with our two examples above, a secondary source would be a journal article or history book which has already written on the subject of 19th-century crop yields. Similarly, an article written by the very journalist trying to find primary sources above would be considered a secondary source.

Essentially, a secondary source is any writing, video, or other form of media which has gathered and interpreted one or a series of primary sources. The big difference between these and primary sources is the interpretation; the basic information about the event or issue, even if presented as objectively as possible, has necessarily been shaped by the person presenting it.

Finding Effective Sources

Now that we've determined the types of effective sources, let's discuss exactly how you should go about finding them. The type of sources that will be useful to you will largely depend upon the question you are trying to answer or the issue you are investigating, but below are some common locations or methods that can help you get started!

The Library

If you are investigating a historical incident, or even if you are investigating something that happened today, the library can be a great place to start your search. Librarians have devoted their careers to understanding and cataloguing both primary and secondary sources, and any librarian worth their weight can usually point you in the right direction after just a short discussion.

Look at Footnotes/Endnotes

Most authors of the books you are researching will list their sources. They may even list the primary sources you need to find, and the libraries or archives where you can go to find them yourself! Footnotes and endnotes, often skipped over by the casual reader, can be a wealth of information concerning effective and worthwhile sources.

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