Archival data refers to data that can be found in archival collections. This can include data that was already collected by a researcher or organization, and has been archived in their files, or could be data that a modern researcher extracts from archival collections. For example, you might consult MC 1204, Betty Bumpers Childhood Immunization Project papers which collected data on childhood immunizations in the 1970s, or you might use the yearbooks as a modern researcher to collect demographic data about the student population. In one case, the data has already been collected, and your might be repurposing it, to compare it to modren data on the same topic, whereas in the other case, you are using a historical source not intended to be used as data (the yearbook) to extract data points from. 

Why use archival data?

While certain research areas or topics necessitate the collection of original data, archival data can be helpful to use in background research about a topic or population for which historical data has already been collected. If your research includes comparing data about a current issue or problem, such as incarceration rates in Arkansas, for example, the historical data about that same issue can help you to make that comparison with data that already exists. 

While collecting archival data takes time and effort, it generally takes much less time than collecting original data. This is especially true if you are looking for data across a broad geographical area. If someone has already collected data on incarceration rates in Arkansas it would take less time to gather that data from existing data sets or published research reports than to go collect it yourself. You may also be able to find more information in archival data than if you conducted data collection yourself, as you have the ability to collect a wider scope of data with archival data than you alone might be able to collect.

Archival data can come in raw forms (data sets, or data you must extract from text or image based sources), or it may have been processed into statistics already (as in the case of some research reports, government documents, etc), making it easier to use in analysis.

Archival data spans diverse disciplines, and can be used in everything from public health to legal to supply chain management to environmental research.