Understanding Confidentiality and Anonymity

Understanding Confidentiality and Anonymity

The terms anonymity and confidentiality are frequently confused in human subjects research. The distinction between the two terms, however, is critical in the design of protocols that protect participant privacy and provide for adequate informed consent.


A condition in which the researcher knows the identity of a research subject, but takes steps to protect that identity from being discovered by others. Most human subjects research requires the collection of a signed consent agreement from participants, and the collection of other personally identifiable data, and thus researchers are aware of the identity of their subjects. In such cases, maintaining confidentiality is a key measure to ensure the protection of private information.

Researchers employ a number of methods to keep their subjects' identity confidential.  Foremost, they keep their records secure through the use of password protected files, encryption when sending information over the internet, and even old-fashioned locked doors and drawers. They frequently do not record information in a way that links subject responses with identifying information (usually by use of a code known only to them). And because subjects may not be identified by names alone, but by other identifiers or by combinations of information about subjects, researchers will often only report aggregate findings, not individual-level data, to the public.


A condition in which the identity of individual subjects is not known to researchers. Because most human subjects research requires signed documentation of consent, subject anonymity is not as common in human subjects research.  Federal law does allow an IRB to waive the requirement for signed consent documents in cases where the collection of that document is the only identifying information linking the subject to the project.  Such documentation is most often waived for projects such as online survey that present no more than minimal risk to subjects.

As you develop your human subjects review application, please be certain you understand the distinction between confidentiality and anonymity, and that you use the appropriate terms in your project description and consent documents.