Preserving Respondent Confidentiality

ICPSR is committed to preserving the confidentiality of respondents. Data depositors are asked to review their data and documentation for information that could identify respondents. More information about approaches to treating confidential data is on the Data Management section of our site.

Deposit Options for Confidential Data

The vast majority of ICPSR data holdings are public-use files with no restrictions on their access. Sometimes the protective measures taken to reduce disclosure risk would significantly reduce the research potential of the data. In these cases, ICPSR provides access to restricted-use versions that retain confidential data by imposing stringent requirements for accessing them.

On the data deposit form, depositors inform ICPSR if the data contain confidential information. If yes, depositors can use the "additional information" box on the form to request one or more of ICPSR's restricted-use data dissemination options described below. Contact ICPSR staff at with questions about any of these options.

  1. Traditional Restricted Data

    For most restricted-use data, ICPSR offers users the ability to request the data via an online form through the ICPSR Data Access Request System (IDARS). Users must be affiliated with a member institution and sign on with a MyData account or with their Facebook or Google passwords. To access ICPSR member-only data, users must be affiliated with a member institution.

    The IDARS application requires:

    • Names, departments, and titles of investigators
    • Description of the proposed research
    • Information on data formats needed and data storage technology
    • Approval for the research project from the Institutional Review Board of the data user's organization
    • A signed data use agreement

    Upon completion, requests are reviewed by ICPSR staff for approval. When approved, the data are sent to researchers on an encrypted CD through the mail with signature required. Please note that ICPSR does not evaluate the validity of the research question; we merely evaluate the security measures undertaken by the researcher and verify that all the necessary paperwork has been submitted.

  2. Physical Data Enclave

    Approximately 20 studies are only accessible for analysis on-site at the enclave in the basement of the Perry Building in Ann Arbor. The data in the enclave contain highly personal information collected from, for example, prison inmates, victims of violence, or serious criminal offenders. An Application for Use of the ICPSR Data Enclave and Confidentiality Agreement signed by the investigator and an official of the investigator's institution are necessary for access to the enclave, as well as approval of the research project from the relevant Institutional Review Board.

    When using the enclave, several guidelines are in effect:

    • Investigators cannot bring laptops or other electronic equipment into the enclave.
    • The enclave computer is equipped with a Windows-based computer with the Microsoft Office Suite, and the SPSS, SAS and Stata statistical packages. Arrangements must be made in advance for other software.
    • The computer cannot send e-mail or access the Internet, and the removable media ports are disabled.
    • An ICPSR staff member is present at all times when a researcher is using the enclave. The monitor inspects and approves all material brought into the enclave, and oversees use of the enclave printer.
    • All output, notes and other material must be electronic and submitted for disclosure review before the investigator leaves the enclave.
    • An ICPSR unit manager will conduct a disclosure review of all files that the investigator wants to use after their use of the enclave.
    • Approved analysis output will be sent to the researcher on media supplied by ICPSR.
  3. Restricted Online Analysis

    For selected restricted-use datasets, ICPSR utilizes Restricted SDA (Survey Documentation & Analysis), an online statistical package that evaluates output for disclosure risk prior to displaying it for the end user. Restricted SDA is programmed to disable access to the microdata and selected variables, evaluates dataset-specific thresholds, and logs user interactions so that usage can be monitored. More detail can be found in the documentation for SDA 3.5.

  4. Delayed Dissemination

    ICPSR can preserve data under a delayed dissemination model, in which the depositor and ICPSR establish a release date. ICPSR preserves the data until that date and distributes it according to the dissemination plan afterwards.