The University of Southampton
University of Southampton Institutional Repository

Preserving edits when perturbing microdata for statistical disclosure control

Shlomo, Natalie and De Waal, Ton (2005) Preserving edits when perturbing microdata for statistical disclosure control , Southampton, UK Southampton Statistical Sciences Research Institute 13pp. (S3RI Methodology Working Papers, M05/12).

Record type: Monograph (Working Paper)


To protect individuals in microdata from the risk of re-identification, a general perturbative method called PRAM (the Post-Randomization Method) is sometimes used for masking records. This method adds “noise” to categorical variables by changing values of categories for a small number of records according to a prescribed probability matrix and a stochastic process based on the outcome of a random multinomial draw. Changing values of categorical variables, however, will cause fully edited and clean records in microdata to start failing edit constraints resulting in data of low utility. In addition, an inconsistent record pinpoints to a potential attacker that the record was perturbed and attempts can be made to unmask the data. Therefore, the perturbation process must take into account micro edit constraints which will ensure that perturbed microdata satisfy all edits. Macro edit constraints which take the form of information loss measures also need to be defined in order to ensure that the overall utility of the data will not be badly compromised given an acceptable level of disclosure risk. This paper will discuss methods for perturbing microdata using PRAM while minimizing micro and macro edit failures. (Updated 10th August 2005)

PDF 14725-01.pdf - Other
Download (248kB)

More information

Published date: 25 February 2005


Local EPrints ID: 14725
PURE UUID: da83e0c3-6645-4ff4-82a4-554e13d3f77d

Catalogue record

Date deposited: 25 Feb 2005
Last modified: 17 Jul 2017 16:53

Export record


Author: Natalie Shlomo
Author: Ton De Waal

University divisions

Download statistics

Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.

View more statistics

Atom RSS 1.0 RSS 2.0

Contact ePrints Soton:

ePrints Soton supports OAI 2.0 with a base URL of

This repository has been built using EPrints software, developed at the University of Southampton, but available to everyone to use.

We use cookies to ensure that we give you the best experience on our website. If you continue without changing your settings, we will assume that you are happy to receive cookies on the University of Southampton website.