michelle simard joint unece/eurostat work session on statistical data confidentiality
DESCRIPTION
Progress on Real Time Remote Access. Michelle Simard Joint UNECE/Eurostat Work Session on Statistical Data Confidentiality Tarragona, Spain, November 23 rd , 2011. Since 2009. Developed a Prototype o ffering tabulated counts Developed Statistical Disclosure Control (SDC) - PowerPoint PPT PresentationTRANSCRIPT
Michelle Simard
Joint UNECE/Eurostat Work Session on Statistical Data Confidentiality
Tarragona, Spain,
November 23rd , 2011
Progress on Real Time Remote Access
23-04-20Statistics Canada • Statistique Canada2
Since 2009
Developed a Prototype offering tabulated counts
Developed Statistical Disclosure Control (SDC)
Continued development on different fronts
23-04-20Statistics Canada • Statistique Canada3
EFT
RTRA Server
SAS Server
Data
CRMS Metadata
Autorisation
E-FT NET BINBOX
E-FT Net A INBOX
Air Gap
Confidentiality
Researcher
The Prototype
23-04-20Statistics Canada • Statistique Canada4
Spring 2010 Tabular(counts) outputs only - SAS only Modified PROC FREQ, Data steps Limited to particular household surveys data sets Confidentiality automated, no manual intervention Limited to some Canadian Federal Departments only Ability to query RTRA micro data at any time Access from any computer with internet access, using a secure
username and password No travel to Research Data Centres
The Prototype
23-04-20Statistics Canada • Statistique Canada5
Minimum 4 minutes plus process time Maximum 3 hours plus process time
Email notification for outputs with 7-day retention Formatted table in HTML or in SAS
The Prototype
23-04-20Statistics Canada • Statistique Canada6
Additive and Controlled Rounding (ACROUND)• Create rounded additive table close to original table
with controlled grand total→ semi-controlled rounding
• Use an iterative process to improve the semi-controlled result
→ controlled rounding
• Protects against possible matching of information with PUMF and small impact on precision
• Maximum : 5 dimensions
Current SDC
7
Proc Percentile
Release the percentile only if
1. there are at least n1 observations ≥ the percentile value and at least n2 observations ≤ the percentile value
2. it is ≠ minimum or maximum value
3. the total number of unweighted observations is ≥ m
4. the rounded frequency associated (from ACROUND) with the percentile is ≠ 0
Statistics Canada • Statistique Canada 23-04-20
Recent Development
8
Proc Mean
Release the mean only if
1. there are at least n3 observations present in the domain
2. the rounded frequency associated with the mean (from ACROUND) is ≠ 0
For both PROC, “magnitude” rounding will be applied on statistics to balance precision and noise
Statistics Canada • Statistique Canada 23-04-20
Recent Development
Not only balancing confidentiality and precision BUT quality measures as well
Evaluating the risk
Displaying information (What and How)• Statistics, Standard Error(SE), Variance, Coefficient of Variation
(CV), Confidence Interval (CI),Quality Indicator (QI), weighted counts, unweighted counts, ACROUND outputs?
23-04-20Statistics Canada • Statistique Canada9
Challenges and Issues
10
Value of CV*Quality
IndicatorGuideline
0 ≤ C.V. ≤ 0.10 (a) very good0.10 < C.V. ≤
0.20 (b) acceptable
0.20 < C.V. ≤ 0.35
(c) marginal
C.V. > 0.35 (d) very poor
Quality Measures
Release estimate with SE and a Quality Indicator (QI) If not releasable ==> put ‘X’s or other symbol otherwise release SE and QI as follows:
*Note: CV is calculated from original non-rounded S.E. and percentileStatistics Canada • Statistique Canada 23-04-20
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Next steps
Used output control techniques rather than input control techniques
Next step: proportions, ratios, totals, models May need input control techniques when going into modeling
Expansion to the academic community Expansion to Censuses, then administrative data Streamlining the approval processes Developing a “fee” structure and “penalty” processes
23-04-20Statistics Canada • Statistique Canada12
THANK YOU
For more information, Pour plus d’information,
please contact: veuillez contacter :
Michelle Simard