Towards a high quality 2011 Census
The Census Field Operation and
LA liaison
Pete Benton
Deputy Director, Census Programme
Overview
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Field operation aims
Field operation design
The key role of Local Authorities
Address register development
2011 Census aim
• “To provide high quality, value for money
population statistics as required by key
users, on a consistent and comparable basis,
for small areas and small population groups”
Field operation objectives
• Historically
– Count everybody
– But falling response rates over time
• 2001
– Count as many as you can
– Then adjust for undercoverage
• 2011
– Count as many as you can
– Do better in the worst 5% of LAs than 2001
– Minimise variability in response within LAs
Overall response & CI with different levels of
variability across enumeration districts
4.0%
3.5%
3.0%
CI Width
7% variability
10% variability
2.5%
12% variability
15% variability
2.0%
1.5%
1.0%
70%
80%
90%
Census Response
100%
Challenge
• Complex response goals
• ‘Real time’, detailed management information
needed
• Flexible but simple field management
approach needed
Field operation design – overview (1)
• Develop high quality address register
• Barcode every questionnaire and link to an
address
• Post Out, Central Post back
• 24 hour receipting, update questionnaire
tracking info
• Identify every non-responding address
Field operation design – overview (2)
• Team-based follow up
– Large team areas where high response expected
– Small team areas where low response expected
– Predictive model built using 2001 census/CCS data
• Divide non-responding addresses into
‘workloads’
– Low response areas – fewer addresses per person
– High response areas – more addresses per person
• Update allocations weekly
• Subject of further development
The key role of LAs
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Contribute to address register development
Provide enumeration staff
Local publicity
Provide local accommodation / logistical
support
• Provide local area information on hard to
count groups etc
• Facilitate access to local community groups
• Appoint Census Liaison Manager (Exec level)
and Assistant Census Liaison Manager
Strong partnership developing
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CLIP census subgroup
LA liaison pilot in 2007 census test
Regional Champions
SOLACE
Workshops with LLPG regional chairs
Current Address register Pilot with 24 LAs
Liaison with LAs in 2009 census rehearsal
LA Liaison - Rehearsal LAs
• LA Liaison programme underway
• First visits to Rehearsal LAs in April 08
– Lancaster, Newham, Isle of Anglesey
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LA Census Liaison Managers confirmed
All 3 LAs enthusiastic and committed
Outline information about areas collected
Action plans being reviewed
Address register development strategy
• ONS matches 3 national address files
– Royal Mail - PAF
– IDeA - NLPG
– Ordnance Survey – AL2
• Matching based on address reference, text and spatial
relations
• Mismatches sent to IDeA, RM and OS for resolution
• Remaining mismatches sent to LAs for resolution
• ONS checks addresses on ground in c. 30% of areas
where most uncertainty remains
• Ongoing change updates from OS and IDeA
• Currently piloting with OS, IDeA and 24 LAs
Partnership and Communications
Working Arrangements for Success
• National Address Register Steering Group
setup to provide strategic direction
• Ongoing dialogue and regular meetings with
suppliers
– Data sharing agreement signed by all parties for the
pilot – a major achievement which will support a
future National Data Sharing Agreement
• Communication to all LAs coming shortly from
regional champion
– Clear messages prepared; workshop 10th October
Results from address matching
• Projected target results presented in July 08
• ‘First cut’ results achieved by August 08
• ‘Second cut’ results achieved by September 08
Matching algorithm
Projected
First Cut
Sec Cut
Reference match
72 %
72 %
72 %
Textual match
87 %
87 %
88 %
Spatial match
89 %
89 %
90 %
Unmatched address resolved
automatically by ONS
94 %
95 %
97 %
Unmatched address resolved
automatically by suppliers
95%
97%
98-99%
Unresolved address residual
to LAs
5%
3%
1%
Challenges & Key lessons Learnt
• Frequent synchronisation of address data from suppliers – from
monthly to either weekly or daily
– need to use latest versions of data
• The importance of VOA and alias addresses in the matching
process
• Avoiding duplication of work already done by other parties
• Improve LA boundaries in PAF
– Estimate this will reduce unresolved addresses by 0.5 %
• Incorporate matching processes of address data suppliers into
ONS methodology to further improve Quality and Confidence in
matching process
Going Forward
• Address matching has proved to be very successful
• The real challenges going forward are:
– Capturing New Addresses
– Identify Multiple Occupancy
• Consequently ONS is planning to conduct
comprehensive Address Field Checking Exercises
across circa 30% of the country
– Current pilot will help development of predictive model to
identify where to address check
Address register timetable
Nov 08
Dec 08
Through 09
Through 09
Dec 09
March 10
Sept 10
Nov 10
27 March 11
Pilot complete
National address matching starts
Anomalies to national providers
Residue to LAs, by region
LA resolution complete
ONS address check starts
Address check complete
Address list to printers
CENSUS DAY
Summary
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Far more control of field operation
Refined objectives
Increased targeting of resources
Builds on 2001 experience
Address register and LA role are key
Message to LAs:
– Appoint CLMs and ACLMs
– Work on your address lists now to improve PAF
consistency
– Further communication coming soon …