Restricted Data


Data are typically classified as restricted if they contain particularly sensitive confidential information about the participants. This might include reports of sexual behavior, criminal history, drug use, mental health history, HIV status, information collected from minors, or other materials that warrant extra discretion.

DSDR and its data providers take the confidentiality of these subjects especially seriously. Data held by DSDR never contain direct identifiers, but there is still a risk that participants in these sensitive studies could be identified indirectly. Using a handful of a known participant's demographic characteristics, a person could narrow down the sample significantly and infer which responses belong to the subject they seek. This is called deductive disclosure risk. One way to counteract this risk is by restricting access to the data and carefully reviewing each applicant to ensure that the data are being used strictly for research purposes.

Applying for Access

DSDR uses a system called IDARS (the ICPSR Data Access Request System) to automate the submission and review of restricted data requests. The system allows applicants to complete their application entirely online, providing project information and uploading relevant documents in a unified interface. DSDR staff then reviews and approves their applications.

We have found that reviewing restricted data requests using IDARS rather than manually can lower administrative costs by up to 26 percent. DSDR is working to produce better estimates of the costs of reviewing requests and establish realistic fees for this process. To achieve this goal, we will work closely with PIs to establish guidelines for fees and a projected fee schedule. Additionally, one of DSDR's partners has been actively testing the ease of use of ICPSR's Virtual Data Enclave (VDE) system. The advantage of this system is that it lets users access high-risk restricted data without having to travel to ICPSR to use a specially-equipped room. We expect that as we develop the electronic catalog and build the DSDR collection, there will be more opportunities for the use of the VDE.

Researchers who want to use restricted data must complete and submit a request online via IDARS.

graphic listing the steps below
  1. Fill in the Online Form: The request form requires investigator and research staff information, a brief description of the research for which the data will be used, and answering a series of confidential data security plan questions.

  2. Upload Request Materials: Applicants must also upload some materials of their own. Evidence of IRB approval or exemption is required. Additionally, applicants must upload the Restricted Data Use Agreement, signed by the investigator and an institutional representative who has the authority to sign legally binding agreements on behalf of the institution. Some restricted data also require the payment of an application fee.

  3. Review of Request: When the request is complete and submitted, DSDR staff review all the materials. During the review process, electronic confidentiality pledges will be sent to the investigator and all research staff members.

  4. Request Returned to Applicant: If there are any problems or incomplete sections, the request may be returned to the applicant with an explanation of what changes need to be made. It is rare for a request to be filled out perfectly on the first submission, so initial rejection is very common.

  5. Resubmission: If the request was rejected, the applicant must make the requested changes and resubmit the request through IDARS.

  6. Request Approval: After any errors in the request have been corrected, the confidentiality pledges are signed, and payment is received, DSDR staff will approve the request and make arrangements for data to be sent to the investigator.

  7. Data Delivery: Our data services specialist sends the data via email in an encrypted download.

Any modifications to an active agreement -- such as the addition of research staff, uploading an IRB renewal letter, or requesting additional datasets -- are subject to the same review process. These changes should be made within IDARS, and the request must be resubmitted online for review.

The entire process from submission to approval takes about one month on average, but it can range from one week to two months. The length of the review process varies based on the quality of the request when it is submitted, the responsiveness of the investigator throughout the review process, and the volume of requests being reviewed by DSDR at any given time.

In addition to the above diagram and outline, the following tutorial videos may be helpful in beginning a request:

  • Introduction to IDARS: This video provides a general overview of IDARS and its part in ICPSR data sharing.

  • IDARS Tutorial - People: This video provides more specific information about the different people and roles associated with a restricted data application.

Frequently Asked Questions

How Does DSDR Protect Respondent Confidentiality?

DSDR ensures respondent confidentiality by removing, masking, or collapsing variables within public-use versions of the datasets. Sometimes these protective measures that are taken to reduce disclosure risk would significantly degrade the research potential of the data. In these cases, DSDR provides access to restricted use versions that retain confidential data by imposing stringent requirements for accessing these data.

What is Restricted Data?

DSDR frequently restricts the access and use of datasets containing information that might compromise the anonymity or privacy of individuals. In particular, any dataset that includes information regarding populations at higher risk of deductive disclosure (such as children, adolescents, prisoners, and parents) is especially likely to be released as restricted.

View a sample restricted use data agreement.

How Do I Access Restricted Data?

Users who wish to access restricted data must submit an application via ICPSR's online Data Access Request System (IDARS). By submitting an application via IDARS, users agree not to compromise the anonymity of individuals.

What is the ICPSR Data Access Request System (IDARS)?

DSDR offers a basic service allowing users to fill out an online application for restricted data access through the ICPSR Data Access Request System (IDARS). To access the IDARS system, users must sign on with a MyData account or with their Facebook or Google passwords.

After a researcher completes and submits the application, DSDR carefully reviews and approves the request. The data are then emailed to the researcher in an encrypted download link. Please note that DSDR does not evaluate the validity of the research question; rather, we assess the security measures undertaken by the researcher to prevent disclosure risk.

Where is the Link to Log into IDARS?

Users can access the IDARS system through the following steps:

  1. Search for a study in the "Search Holdings" page
  2. Click on the desired study in the "Study Search Results" page
  3. Navigate to the "Access Notes" section of the study page
  4. Click on "apply online for access to the data"

How Long Does it Normally Take to Receive Restricted Data?

The time it takes for a researcher to receive restricted data varies and depends on several factors. These factors include the quality and completeness of the researcher's application and the number of applications DSDR receives at any given time. On average it takes 3 to 5 weeks for an application to be approved and for the data to be sent to the researcher.