Data with Confidential Content
For all research projects, respondent or subject confidentiality is always a concern. Investigators are asked to review the data prior to submission to determine if the data contain information that would allow any individuals or organizations under human subjects protection to be identified.
Direct Identifiers
Most familiar are the direct identifiers that may have been collected during the course of the project. Examples of direct identifiers include:
- Names
- Addresses, including ZIP codes
- Telephone numbers, including area codes
- Social Security numbers
- Other linkable numbers such as driver license numbers, police officer badge numbers, prisoner identification numbers, etc.
Indirect Identifiers
Variables that can also be problematic are the indirect identifiers that may be used in conjunction with publicly-available information to identify individual respondents. Decisions about these variables depend on the content of the data collection and the nature of the research subjects included in the dataset. Examples of indirect identifiers include:
- Detailed geographic information (e.g., state, county, or census tract of residence)
- Organizations (to which the respondent belongs)
- Educational institutions (from which the respondent graduated and year of graduation)
- Exact occupations
- Place where respondent grew up
- Exact dates of events (birth, death, marriage, divorce)
- Detailed income
- Offices or posts held by respondent
Depositing Data with Identifiers
NACJD prefers to receive the original (non-sanitized data) for preservation purposes. NACJD archiving activities to process data for release include conducting a confidentiality review and using information provided by the depositor to create data files that can be released via the NACJD Web site and/or through one or more of the Restricted Data Access (pdf 16K) or Delayed Dissemination options.
Pursuant to U.S. Department of Justice regulations (28 CFR 22), all fields directly identifying the research subjects must be deposited in a separate data file from the file that contains the research data. Therefore, if the data contain direct identifiers and/or contact information, i.e. a roster file with names, addresses, etc, these should be saved along with a linking case id variable(s), in a separate file (e.g. SPSS system file). The remaining research data with the linking variable(s) are submitted in a second file.
The use of a compression program such as WinZip is recommended to separately encrypt with a password the research file and subject roster file. The encrypted research file should be deposited using the online deposit form (or on a CD-R or DVD). Depending on its size (less than 3 MB zipped) the roster file can be emailed to nijdeposits@icpsr.umich.edu or shipped separately on a second CD-R or DVD using a method that provides tracking of the package. The password used to encrypt the roster file and the research file can be sent in separate email messages to NIJ Deposits (nijdeposits@icpsr.umich.edu). This approach is consistent with U.S. Department of Justice regulations that require the storage of identifiable information separately from the research files.
The Restricted Data Access (pdf 16K) option best balances retaining needed analytic information, yet providing limited and controlled access to the data. Depositors are encouraged to recommend an appropriate level of data access for the data that they deposit.
Depositors can contact NACJD staff with any questions they have about how to prepare the data with confidential content for deposit or to discuss Restricted Data Access (pdf 16K) or Delayed Dissemination options. NACJD staff available by email at nacjd@icpsr.umich.edu, or by phone at 800-999-0960.
