Confidentialising Microdata : Aims
To confidentialise microdata, the ABS aims to protect the data against two specific disclosure risk scenarios: spontaneous recognition and matching to lists.
Spontaneous recognition occurs when a user, while looking at information on a microdata file, happens to notice some unusual characteristics which remind her/him of someone that they know. Looking further at other data items can confirm the identity.
List matching occurs when two datasets could be matched via common variables and, in cases where the matches are one-to-one, the combined set of variables pose an additional disclosure risk. As administrative lists often contain similar demographic variables (age, sex, geographic location, etc.) as the ABS microdata, the risk of list matching to administrative lists is assessed.
For basic CURFs, the aim is to protect against both the spontaneous recognition and the list matching risk. For expanded CURFs, the aim is to protect the data against spontaneous recognition only, as extra protections are built into the Remote Access Data Lab infrastructure to protect list matching. The 2004 work program for the Data Access and Confidentiality Methodology Unit includes conducting research to improve methods for assessing and addressing the spontaneous recognition and list matching risks, as well as developing software tools to make these processes more efficient.
For more information about confidentiality, please contact Kirsty Leslie on (02) 6252 5594 or Paul Schubert (02) 6252 7306.
Email: kirsty.leslie@abs.gov.au or
paul.schubert@abs.gov.au