Week 4 - Anonymisation

Question 1

How could a person be identified?

Answer 1

Direct identifiers: name, address, postcode etc

Indirect: occupation, geography, unique or exceptional values

Question 2

List the key points for anonymisation

Answer 2

• Reason/Purpose for anonymising
• Never disclose personal data without consent
• Reasonable level of anonymity
• Maintain meaningful info
• Replace rather than remove
• Re-users of the data have the same obligation to not disclose confidential info

Question 3

How to anonymise quantitative data?

Answer 3

• Remove direct ids
• Reduce precision
• Restrict upper/lower ranges to hide outliers
• Combine variables

Question 4

How to anonymise qualitative data?

Answer 4

• Don’t collect revealing data unless necessary.
• Edit at time of transcription except longitudinal studies (when complete)
• Avoid blanking out, use pseudonyms
• Avoid over-anonymising
• COnsistency
• Keep anonymisation log - keep separately.
• Phrases can identify certain backgrounds so be aware

Question 5

How to anonymise video and images?

Answer 5

• Don’t just black out eyes
• Tattoos or hair may identify
• Remove location identifiers

Question 6

Types of Access Control

Answer 6

• Open Access
• Metadata only – contact details for requesting data reuse, End User Licence
• Dark Archive
• Embargo for given time period

Question 7

Can data ever be totally anonymous?

Answer 7

No, https://www.theguardian.com/technology/2019/jul/23/anonymised-data-never-be-anonymous-enough-study-finds