Types of Sources


Archives are typically a collection of historical records or the physical place in which they are located. They are usually PRIMARY source documents that have been gathered together - sometimes to show the function of a particular person or organization. Some archives are private institutions and may not have the funding to completely digitize all of their resources, so they require you to go in person to search. Some examples include:

  • Brooklyn Public Library has an archive of materials documenting the history and people of the Borough of Brooklyn and it can be accessed in person or through their digital collections online.
  • The Digital Public Library of America collects over 35 million images, texts, videos, and sounds from libraries, archives, museums, and other cultural heritage institutions. All of their digital collection can be searched online here.


Databases are subscriptions that provide access to a variety of scholarly (peer-reviewed) journals as well as trade magazines and newspapers. Typically they are SECONDARY sources, but can sometimes be primary sources (i.e., newspaper articles). Many databases are considered "gated," meaning they require a password or authentication to access. Below are a list of databases you may want to use for research that are available through these links anywhere in the state of NY (so you can view them at home, too). Additional databases can be accessed through the Brooklyn Public Library your Brooklyn Public Library card. Some examples include:

Encyclopedias are reference materials that are a TERTIARY source; that means they are created from both primary and secondary sources. They are extremely useful in order to get background information and keyword to use in your next search. Be aware of "online encyclopedias" that include a lot of advertisements or do not have a date or author listed. Some examples include:

  • Encyclopedia Britannica Academic Edition is a subscription-based encyclopedia available anywhere within the state of New York (authenticate with your location). Britannica is also available in Spanish!
  • Wikipedia is the world's largest free encyclopedia, but anyone can contribute and change an article. Wikipedia is a great place to start the research process and learn more about your topic; look for search terms to take to scholarly journals, databases, and archives to complete your research.

*It is important to note that an encyclopedia article provides a brief overview of a topic area while a scholarly journal article provides specific research information on a specific topic. Be sure you know if your database is searching encyclopedia/reference, popular magazine and newspaper articles, or scholarly journals.