Presentation on theme: "IMPROVING CONFIDENTIALITY WITH tau-ARGUS BY FOCUSSING ON CLEVER USAGE OF MICRODATA Roland van der Meijden MSc. ± 10 minutes."— Presentation transcript:
IMPROVING CONFIDENTIALITY WITH tau-ARGUS BY FOCUSSING ON CLEVER USAGE OF MICRODATA Roland van der Meijden MSc. ± 10 minutes
Content of presentation tau-Argus Tuning possibilities Hierarchies Historyfile, information loss and base material Conclusions
Tau-Argus Automated cell suppression software Calculates confidentiality effects on all dimensions of a table simultaneously Offers 4 confidentiality rules: -(n,k)-rule / dominance rule -p%-rule -p-q-rule / prior-posterior-rule -Minimum frequency rule
Tuning possibilities Hierarchies: The way hierarchies are built is of influence on how secondary suppressions are applied. History file: A preference can be given for which cells may or must be secondarily confidential. Information loss weights: Information will be lost when applying secondary suppressions. The way tau-Argus calculates this information loss can be adjusted. Base material: The way the microdata and preferred output are composed is of influence on the way secondary suppressions are applied.
Hierarchies (2) Status narrow size class size class total size class S - L size class A - E size class % cells A frequency unsafe 32,842,052,961,4 D secondary unsafe 27,231,525,117,9 V safe 35,125,121,520,4 Status wide size class size class total size class S - L size class A - E size class % cells A frequency unsafe 32,841,149,361,4 D secondary unsafe 26,531,528,418,1 V safe 35,725,821,620,2
Historyfile, information loss and base material (1) Historyfile – Confidential, publishable, preferably do (not) suppress secondarily Information loss – Cell value, frequency, equal and distance Base material – Small area estimation, deliberately adjusting microdata and coordination of publication obligations
Historyfile, information loss and base material (2) Methods for determining information loss Cell valueFrequency Status 2 nd digit NACE 3 rd digit NACE 4 th digit NACE 5 th digit NACE 2 nd digit NACE 3 rd digit NACE 4 th digit NACE 5 th digit NACE A frequency unsafe B dominance unsafe D secondary unsafe V safe
Conclusions - tau-Argus is a tool that is helpful in calculating confidentiality effects. - The confidentiality pattern can be influenced. - Improving the confidentiality pattern, takes a lot of effort. - Both tooling and the way base material is used are of influence on the confidentiality pattern.