Data privacy is important for research because it protects the participants' rights and dignity and influences their willingness to take part, it also assists researchers in complying with ethical and legal obligations associated with their work. Pseudonymisation is a technique that protects data privacy while allowing researchers to safely analyse data.
Unlike anonymisation, which irreversibly removes all identifiers, pseudonymisation replaces specific identifying information with artificial identifiers, allowing data to be linked to the original source with access to a unique key.
It’s crucial to remember that pseudonymised data is still personal data under data protection legislation, retaining its obligations and protections. On the other hand, anonymised data is not subject to data protection regulations.
Here’s an example, Ash was a researcher who wanted to study the effects of social media on mental health. They had recruited some volunteers who agreed to share their online activity and psychological assessments with them. They knew that this data was very sensitive and personal, and they had to protect the privacy of their research participants, so they decided to use pseudonymisation.
Ash replaced the names, usernames, and email addresses of the participants with random codes. They also removed any other details that could reveal the participants’ identities, such as profile pictures, location, or personal messages. Ash ensured that the details remaining in the pseudonymised data set could not be combined and allowed participants to be reidentified. They stored the key that linked the codes to the real identities in a secure place, separately from the data, and only shared it with their research team.
Ash's story shows how pseudonymisation can be used to enable research and innovation while respecting the privacy of the research participants. By using pseudonymisation, Ash was able to conduct their research in a responsible and ethical manner and contribute to the advancement of knowledge and society.
For examples and further information on pseudonymisation please see our guidance How identifiable is your data? or contact your School/Service’s Data Co-ordinator. If you’re interested in anonymisation please consider watching the UK Data Service's video on anonymising data or reading the code of practice on Anonymisation: managing data protection risk produced by the Information Commissioner’s Office.