The Source for Crime and Justice Data

New User Tutorial

What You Will Get From the NACJD Archive

Most of the datasets in the NACJD archive are raw data from surveys, censuses, and administrative records. They were originally gathered in research projects and for administrative purposes. ICPSR preserves them because they have value for "secondary analysis" - that is, reexamining old data to address new questions or to employ new analytic methods.

You will not get reports, charts, publications, or other studies from NACJD. Rather, you will get raw numerical data which can be analyzed. Some datasets have been used in published studies. You can see a bibliography of these studies by clicking on the "view related literature" link on each study's home page.

Finding the Data You Need

Use the Search Box if you know exactly what you want. For example, enter a survey title or the name of a principal investigator in the search box. We also offer several browse options, including:

NACJD makes use of faceted searching. You may find it helpful to read over a brief post on Faceted Searching Using SOLR.

Terminology

In your searching you may encounter unfamiliar acronyms and specialized terms used in the social sciences. These resources can provide clear definitions:

Obtaining Access to the Data

Documentation

All of the documentation files associated with ICPSR datasets are available to the general public. This documentation includes the study metadata--that is, the data describing the study. However, not all of the datasets themselves are freely available.

Restricted Data

Some datasets are protected because there is a risk that the identity of research participants could be disclosed. These datasets are released with special protections. Datasets in which the level of disclosure risk is especially high can be examined only in a special data enclave in the ICPSR office in Ann Arbor. See enclave data.

If you find a dataset with restricted access, you will see an Access Note about this on the study home page:

example of a study home page with a restriction note
example of a study with a restricted access note

Downloading Data

When you find a study that you wish to download, you will see a variety of download links on the study home page that enable you to download individual documentation files, or application-specific bundles (at either the study or dataset level). The "Quick Download" button provides multiple options on mouse over.

Before downloading the data, you may want to do two things to assure that the study meets your needs.

Note that in downloading data from NACJD, you signify that you agree not to share the data with anyone not authorized by ICPSR to receive it. You further agree to the terms of use.

Analyzing Data

Using the downloaded data requires some basic knowledge of statistical analysis techniques and some familiarity with statistical analysis software packages. We provide help for specific analysis packages and data analysis issues.