Notes on sensitivity measures and protection levels

Anneke Loeve
Statistics Netherlands

Summary.
At Statistics Netherlands, a heuristic approach for cell suppression in non-negative hierarchical tables, HiTaS, is developed. HiTaS itself makes use of ARGUS, a cell suppression method for the protection of non-hierarchical tables. HiTaS protects a hierarchical table in a top-down approach by finding protection patterns for non-hierarchical sub-tables using ARGUS. ARGUS is based on a method by Fischetti and Salazar. To use this method, the cells which have to be protected are assigned the status primary unsafe. For these cells, non-negative protection levels can be chosen. These protection levels define a protection interval around the cell value. If a cell is primary unsafe, it will be contained in the final protection pattern, along with secondary suppressed cells such that the value of the first cell cannot be calculated to lie within the protection interval. For the determination of the primary unsafe cells, some kind of safety rules are used. Often a combination of a linear sensitivity measure and a number rule will be employed. It would be nice if the choice of the protection levels is related to the rules used to determine the safety of the cells. In this note, some safety rules and their relation with the choice of protection levels are discussed. Keywords: HiTaS, ARGUS, hierarchical tables, cell suppression, (linear) sensitivity measures, protection levels.

Keywords:
HiTaS, ARGUS, hierarchical tables, cell suppression, (linear) sensitivity measures, protection levels.

Address for correspondence:
Anneke Loeve
Statistics Netherlands
P.O. Box 4000
2270 JM Voorburg
The Netherlands
Phone: +31-70-3375528