Using the Complex Measure in an Assessment of the Information Loss Due to the Microdata Disclosure Control

Abstract

The paper contains a proposal of original method of assessment of information loss resulted from an application of the Statistical Disclosure Control (SDC) conducted during preparation of the resulting data to the publication and disclosure to interested users. The SDC tools enable protection of sensitive data from their disclosure – both direct and indirect. The article focuses on pseudonimised microdata, i.e. individual data without fundamental identifiers, used for scientific purposes. This control is usually to suppress, swapping or disturbing of original data. However, such intervention is connected with the loss of some information. Optimization of choice of relevant SDC method requires then a minimization of such loss (and risk of disclosure of protected data). Traditionally used methods of measurement of such loss are not rarely sensitive to dissimilarities resulting from scale and scope of values of variables and cannot be used for ordinal data. Many of them weakly take also connections between variables into account, what can be important in various analyses. Hence, this paper is aimed at presentation of a proposal (having the source in papers by Zdzisław Hellwig) concerning use of a method of normalized and easy interpretable complex measure (called also the synthetic indicator) for connected features based on benchmark and anti–benchmark of development to the assessment of information loss resulted from an application of some SDC techniques and at studying its practical utility. The measure is here constructed on the basis of distances between original data and data after application of the SDC taking measurement scales into account.