Personally Identifiable Information (PII)
What is Personally Identifiable Information (PII)?
Personally Identifiable Information (PII) is any data that can be used to identify a specific individual, either directly or indirectly. This includes information such as names, social security numbers, addresses, and other unique identifiers that can be linked to a person's identity.
Synonyms: Personal Data, Identifiable Information, Personal Information, Individual Identifiers

Why PII is Important in User Research
Protecting Personally Identifiable Information (PII) is crucial in user research to maintain ethical standards and comply with data protection regulations. Researchers must handle PII with care to ensure participant privacy and build trust with study participants.
How PII is Used in User Research
In user research, PII may be collected for various purposes:
- Participant recruitment and screening
- Demographic analysis
- Follow-up studies or interviews
- Incentive distribution
Researchers should only collect PII that is absolutely necessary for their study and implement strict data protection measures.
Examples of PII in User Research
Common types of PII encountered in user research include:
- Full name
- Email address
- Phone number
- Home address
- Date of birth
- Social security number
- IP address
- Biometric data (e.g., fingerprints, facial recognition data)
Frequently Asked Questions
- What's the difference between PII and sensitive data?: PII refers to any information that can identify an individual, while sensitive data is a subset of PII that includes information like race, religion, or health status.
- How long should PII be retained in user research?: PII should only be retained for as long as necessary to complete the research objectives. After that, it should be securely deleted or anonymized.
- Can PII be shared with other researchers or stakeholders?: PII should only be shared on a need-to-know basis and with proper consent from participants. Any sharing should comply with data protection regulations and research ethics guidelines.