Data are made anonymous by what method?

Data are considered anonymous when all identifiers that could link a response back to an individual are destroyed or removed. This process ensures that the data cannot be traced back to the individual who provided it, thereby maintaining the privacy and confidentiality of the respondents.

When identifiers such as names, addresses, or any other personal information are eliminated, the data becomes a collection of responses without any means of associating those responses with specific individuals. This is crucial for ethical research practices, especially in sensitive studies, as it helps protect participants from potential harm that could arise from the disclosure of their personal information.

In contrast, simply keeping a key linking names to responses or reporting data in aggregate form may not completely anonymize the responses. For example, reporting in aggregate form still requires some level of identifiable linking if not done correctly. Signing confidentiality agreements among team members may help ensure that those handling the data maintain privacy standards, but it does not, by itself, achieve anonymity.

Thus, removing all identifiers is the fundamental step that constitutes true anonymization of data, making it the correct answer in this context.