If one selection requested all pets while another requested only furry pets, if the elephant is the only non-furry pet in an area, the two outputs could be differenced to reveal information on the household with the elephant.
Originally developed by the Australian Bureau greece rcs data of Statistics to protect their census outputs, changes to table cells in a consistent way so that a table query will always result in the same values, and the same cell in a different table will always display the same value. We have adapted the method to include changes to zero value cells, which along with Record Swapping, allows small cells to be published in census tables due to the sufficient uncertainty they apply, without significantly changing the characteristics of the outputs.
Automated Disclosure Checks
The final line of defence against intruders is our Automated Disclosure Checks. Even after applying Record Swapping and the Cell Key methods, some tables may be sparse for some geographic areas or categories if too much detail is requested. We can’t manually assess every possible combination of variables within a reasonable timeframe so we have developed a set of rules to look for possible disclosures.