Why is the retention of a separate key for a coding system considered protective?

The retention of a separate key for a coding system is considered protective because it safeguards sensitive information from unauthorized access. In research contexts, especially those involving vulnerable populations such as prisoners, it is crucial to minimize the risk of identifying individual participants’ data in case of data breaches. By using a separate key, the actual identifiers are not stored alongside the coded data, creating an additional layer of security.

This separation means that even if the coded data is accessed by someone without permission, they would not have immediate access to the personal identifiers unless they also obtained the key. This practice aligns with ethical standards and legal requirements regarding confidentiality and data protection, ensuring that participants' privacy is maintained throughout the research process.

In contrast, options related to simplicity, quicker analysis, or methodological enhancements do not address the fundamental concern of protecting personal data, which is why they do not represent the main purpose of retaining a separate key.