Secondary data refers to information that has already been collected by someone else for a different purpose. This is in contrast to primary data, which is information you collect yourself specifically for your current research or study.

• (Read this research guide to learn more about different types of data and research methods).

Secondary data can be incredibly useful for researchers as it allows them to leverage existing information to conduct new analyses without the need for extensive data collection efforts. 

Common sources of secondary data include government records (e.g., census data), academic publications, organizational reports, media articles, and online databases and repositories. 

The following databases are a helpful starting point when searching for your secondary datasets:

For further help conducting your searches for secondary datasets, reach out to your liaison librarian (contact information on the lefthand side of this page).

Raw data is the very first version of data that is collected before anything is done to it. Think of it like the ingredients in a recipe before you mix or cook them together. If you were doing a survey, raw data would be the answers people gave you, exactly as they wrote them down, without any changes or summaries.

Imagine you're collecting information about what types of pets your classmates have. If you ask them to write down their pet's name, type (dog, cat, etc.), and age, all those individual answers are your raw data. It hasn't been organized, cleaned up, or analyzed yet- it's just a collection of responses waiting to be used.