How do I know if I do need restricted data?

Many studies have both public- and restricted-use versions of the data and your research question will dictate whether the restricted version of the data is required. Sometimes the difference between the files is noted in the description or elsewhere on the study homepage, but it’s always a good idea to use the codebooks provided to help you make the decision.

You can access the codebook from the Data & Documentation tab, click the arrow next to each dataset.

Start with the codebook for the public-use file to determine whether the variables you need are included and, if they are, you are good to go! Often the public-use file is perfectly well suited to a given research question. If the variables you need are not included, marked as “masked by ICPSR,” or don’t have enough detail to be useful for your research, look at the codebook for the restricted file to see if they may be included in a different form there.

In the rare instance in which there is no codebook for the restricted file, you can email questions about the files to ICPSR-help@umich.edu .

I need restricted data, now what?

Click on the “Access Restricted Data” button on the study homepage and a pop-up box will appear to inform you of the application process.

The application itself might vary slightly across studies, but typically you will need basic information about the research team, a description of the project that notes why the restricted data are necessary, and supplemental documents such as IRB approval from your institution or curriculum vita. Students need to have a faculty advisor submit the application on their behalf. More detailed information about the application process.

Note: Sometimes restricted data are offered via encrypted download as well as in ICPSR’s virtual data enclave (VDE). The major differences are that the application for data via encrypted download requires information about the security of the computing facilities in which the data will be used, there is sometimes a fee for using data in the VDE, and output generated from analyses in the VDE must be vetted by ICPSR staff prior to being released to the research team.

If you have any questions about a specific ICPSR study and data access, you can email ICPSR-help@umich.edu