Towards a high quality 2011 Census

The Census Field Operation and LA liaison

Pete BentonPete Benton

Deputy Director, Census ProgrammeDeputy Director, Census Programme

Overview

• 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

1.0%

1.5%

2.0%

2.5%

3.0%

3.5%

4.0%

70% 80% 90% 100%

Census Response

CI

Wid

th

7% variability

10% variability

12% variability

15% variability

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

• 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

• 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

• 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 Pilot completeDec 08 National address matching startsThrough 09 Anomalies to national

providersThrough 09 Residue to LAs, by regionDec 09 LA resolution completeMarch 10 ONS address check startsSept 10 Address check completeNov 10 Address list to printers27 March 11 CENSUS DAY

Summary

• 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 …