Confidentiality Review

Following an initial assessment of materials submitted, ICPSR staff review all data and documentation for the presence of confidential information. ICPSR strongly recommends that data producers remove all respondent identifiers prior to deposit of their data collections. Responsible archiving practice demands that ICPSR not release any information that could, on its own or in combination with external data sources, be used to identify respondents. Toward this end:

Direct identifiers are always deleted from data files.

Indirect identifiers are identified and where valid concerns exist, steps are taken to remedy the threat of disclosure. Examples of recoding efforts taken to eliminate indirect identifiers include converting dates to time intervals, exact dates of birth to age groups, state of residence to regional codes, and income to income ranges or categories.

ICPSR staff work closely with data depositors to resolve confidentiality issues, since they are most familiar with the data and in some cases, the altering of data for this purpose reduces the amount of information available for analysis. However, the best solution is for the data depositor to determine, prior to depositing data with ICPSR, whether the confidentiality of individuals is being preserved, and if not, to take the necessary action.