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In tabular data the cell suppression statistical disclosure control (SDC) method consists of primary and complementary (secondary) suppression.

Primary suppression can be characterised as withholding the values of all risky cells from publication, which means that their value is not shown in the table but replaced by a symbol such as ‘×’ to indicate the suppression. According to the definition of risky cells, in frequency count tables all cells containing small counts and in tables of magnitudes all cells containing small counts or presenting a case of dominance have to be primary suppressed.

To reach the desired protection for risky cells, it is necessary to suppress additional non-risky cells, which is called complementary (secondary) suppression. The pattern of complementary suppressed cells has to be carefully chosen to provide the desired level of ambiguity for the risky cells with the least amount of suppressed information.

Source Publication:
Statistics Netherlands, Statistics Canada, Germany FSO, University of Manchester, 2005, Glossary of Statistical Disclosure Control, incorporated in paper presented at Joint UNECE/Eurostat work session on statistical data confidentiality, Geneva, 9-11 October 2005.

Statistical Theme: Methodological information (metadata)

Created on Wednesday, November 9, 2005