Event Slides

1. 2021 Census Collection
Strategy
Chair: Tansy Arthur, Census Transformation
Programme, ONS

2. Census Collection Strategy: what’s
different this time; what we’re testing.
Tansy Arthur

3. Scope of presentation
Collection and supporting activities to
• maximise response
• reduce variability in response
• while also maximising online response

4. Drivers for change
• Move to predominantly online
• Impact of initial contact
• Change to respondent needs
• Definition of “hard to count”
• Lessons learned from 2011
• Field staff communication
• Impact of follow up letters
• Field staff intervention

5. Initial Contact Research and Testing
• Respondent focused research
• Individuals
• Focus groups
• Behavioural insights

6. Change to respondent needs
• Usability testing of an online Census
prototype
• Workshops to develop Census-wide
personas
• GDS assessment

7. Impact of follow-up letters
• More cost effective way to reach
householders
• Particularly useful in areas where it was
difficult to make doorstep contact.
• Similar design research to Initial Contact
• Testing of optimum timing

8. • Dynamic workload allocation
• Timely communication
• Accurate recording of calling patterns
But
• Difficult to find an absolute fit
Field staff communication

9. Field staff communication
• First tests in 2014
• Further testing in 2016

10. Field staff intervention
• What is the most cost-effective use of field
staff in 2021?
• When and where should we intervene?
Build on 2011
• Target field activities
• Look at impact of earlier and later intervention

11. Communal Enumeration
• Evaluate improvements to address register
• Treatment of guest houses and hotels
• Examine support needs
• Improvements to university enumeration

12. Definition of “hard to count”
• Additional complexity of digital dimension
• capability
•opportunity
• We will explore
• assisted digital possibilities
But
• We will respond to user need
• This may include paper

13. Your feedback and questions

14. Maximising Response for a
predominantly online Census
Owen Abbott

15. CONTEXT
Our key objective is to produce high quality
statistics that meet user needs
In order to achieve that we need to:
• Maximise response
• Minimise variability in response
Why?
• The UK Censuses are an estimation process, it is
not a count. The estimation process gets highest
quality under these two conditions.

16. MAXIMISING RESPONSE STRATEGY
There are households and people who require
additional resources to either persuade or
enable them to respond
Hard-to-Count is a term we use to describe
such areas/groups
Examples:
• Digital access/skills
• Students
• Inner City Areas

17. MAXIMISING RESPONSE STRATEGY
Key Challenge:
• Predominantly online census
Strategy:
• Have a coherent approach
• Build on what we did in 2011
• Seek insights based on new data sources
• Be cost effective

18. WHAT WILL WE DO?
• Characterise likely non-responders (and
responders)
• Identify priority and special groups
• Gather evidence to underpin enumeration
strategy
• Allocate resources based on best possible
information
• Ensure coherence across all activities

19. CHARACTERISING NON-RESPONSE
• In 2011 we were able to model non-response
using the CCS and predict response rates
• Identified factors were:
• Age, Tenure, location, ethnicity, family status
• Used to create a general purpose Hard-to-
Count index
• Used updateable data as proxies for above factors
• Split into national 40%, 40%, 10%, 8%, 2%
categorisation

21. 2011 HtC - London

22. CHARACTERISING NON-RESPONSE
• Challenging area given that 2021 Census will
be online first
• Can’t just re-use data from 2011 alone
• Likely to be mix of traditional non-response
factors and an ‘online’ effect
• Key requirement is to predict response levels
prior to follow up
• Plan to use the 2017 Census Test data to
construct non-response model for an online
census

23. CHARACTERISING NON-RESPONSE
• For the 2017 Census Test used two factors:
1. Measure of engagement - used initial
response patterns in 2011 Census as a
proxy
2. Measure of online response – used access
to broadband data from OFCOM as a proxy

24. CHARACTERISING NON-RESPONSE
• Day 10 Return rates

25. CHARACTERISING NON-RESPONSE
• OFCOM map

26. CHARACTERISING NON-RESPONSE
• At LSOA level split each into 3 strata
• (Using Dalenius-Hodges rule)
• Combined these into 9 strata
• 2017 Census Test designed to ensure have
sufficient sample every stratum
High online Medium online Low online
High engagement
Medium engagement
Low engagement

27. CHARACTERISING NON-RESPONSE
• From the 2017 Census Test data we can then
learn about and build models to predict things
like:
• Characteristics of online responders
• Likely online response
• Where to deliver paper
• Where digital assist might be required
• …although we will need to find updateable data
sources which correlate with the outcomes…
• Exploring IMD style Hard-to-Count typology

28. RESOURCE ALLOCATION
• Build on 2011 Census targeting:
• Higher follow-up initial resource in areas expected
to obtain low initial response
• For 2021:
• More responsive and timely follow-up actions
• Moving resource to lowest responding areas
• More sophisticated targeting?
• At address level?
• Age-sex groups from admin data?
• Vacant households?

29. OTHER ACTIVITIES
• Developed a Field Operations Simulation
Model to help understand impacts of different
strategies
• Discrete Event Simulation approach
• Target Population Matrix
• Identify and plan activities for specific groups for
which there is a specific risk of under-enumeration

30. IDENTIFY PRIORITY GROUPS
• Activity Summary (this is extract from 2011)

31. SUMMARY
• Maximising response and minimising
variability in response is key strategic aim
• Approaching this much in the same way as in
2011
• Building on what was achieved
• Looking for opportunities to use additional
sources of data for more efficient targeting of
resources
• Ensuring coherent end-to-end design

32. Evaluating the 2017 Census Test
Cal Ghee
ONS 2021 Census Statistical Design

33. What are we covering?
• What the objectives of the 2017 test are
• What the statistical design of the test is
• Criteria for choosing test areas
• What the next steps are
• Your feedback…

34. Objectives
What are we testing?

35. Components of the Census operation
• Online data collection service
• Response management
• Hand-held devices for use by field staff
• Public support – digital assistance
We need to gain an understanding and be able
to assess how our systems perform with online
first:

36. Objectives – what we’re testing in 2017
Our main statistical objectives:
• The effect on the number of responses and
the quality of response when a question on
sexual identity is included
• Methods for maximising self-completion
(maximising response before introducing
field staff into the follow-up operation)
• Options for the field design to optimise
overall response

37. Objectives – why we’re testing them
• Sexual identity– to help inform whether we
include this question or not
• Maximising self-completion – to reduce
complexity and costs of field follow-up work
• Field follow-up options - to optimise overall
response by maximising responses but also
minimising variability in response
• Can we predict paper questionnaire
requirement

38. Test design
How has the testing been designed?

39. Design – how we’re testing in 2017
Three component test approach:
• Component 1 – with field follow up
• Component 2 – without field follow up (optimising
self-completion)
• Component 3 – validation of communal
establishment enumeration

40. Component 1: Evaluation
• To gauge effect on response (and quality of
response) of the inclusion of a question on
sexual identity
• Includes providing paper questionnaires to ensure
we don’t exclude any groups
• Testing field follow up options to optimise
response and minimise variability in response
rates across areas
• How effective is field follow-up? Can we go earlier
or later? Who responds to visits or reminder
letters? Does going earlier ‘waste’ time on people
who would have responded anyway?

41. FIELDFOLLOW-UPFINISHES17MAY
May
week 6
CENSUSTESTDAY9APRIL2017
EASTER
FRIDAY14TO
MONDAY17APRIL
School holidays BH
March April
week -3 week -2 week -1 week 1 week 2 week 3 week 4 week 5
-21 -14 -7 +7 +14 +21 +28 +35
Component 1
IACs posted out (q're
with sexual identity
question)
IACs posted out (q're
without sexual
identity question)
Field follow-up in 'harder' areas in treatment sample
Field follow-up in 'harder' areas in treatment sample
Field follow-up in control sample
Field follow-up in control sample
Field follow-up in 'easier' areas in treatment sample
Field follow-up in 'easier' areas in treatment sample
provide paper
questionnaires on
request
Send
reminder
Send
reminder
Send
reminder
Component 1: 2 x 2 test with field follow up
– new question and collection design
50,000 households
50,000 households

42. Component 2: Evaluation
• To demonstrate the effectiveness of
reminders, understand real underlying self
response rates
• To assess whether there is a difference in
response rates, and the type of respondents,
when sending IAC only or paper
questionnaire.
• What types of people request paper
questionnaire?
• What types of people still respond online
when they received a paper questionnaire?

43. Component 2: optimising self-completion,
no field test
IACs posted (q're with
sexual identity question)
IACs posted (without
sexual identity question)
Paper qu’resposted (with
sexual identity qu)
Paper qu’res posted
(without sexual identity)
Send
reminder
Send
reminder
Send
reminder
provide paper
questionnaires on
request
FIELDFOLLOW-UPFINISHES17MAY
May
week 6
EASTER
FRIDAY14TO
MONDAY17APRIL
School holidays BH
March April
week -3 week -2 week -1 week 1 week 2 week 3 week 4 week 5
-21 -14 -7 +7 +14 +21 +28 +35
CENSUSTESTDAY9APRIL2017
Component 2: continuation of sexual identity test, including sending paper first
Component 2: testing letters and reminders (all q'res exclude question on sexual identity)
IACs posted out Rem Rem Rem
IACs posted out
IACs posted, diff style
IACs posted later
IACs later, diff style
Remi Remi PaperIACs posted out
Rem Rem
IACs posted out Rem
IACs posted out
Paper
IACs posted, diff style
RemIACs posted, diff style
RemRem Rem
PaperRem
Rem
RemRemIACs posted, diff style
IACs posted, diff style Paper
60,000
house-
holds
40,000
house-
holds

44. Test areas
Where are we testing?

45. What key criteria (I) have we used to
inform our area selections?

46. What key criteria (II) have we used to
inform our area selections?

47. Areas being used for the field follow-up
component of the 2017 test
• Barnsley
• Blackpool
• Powys (North)
• Sheffield
• South Somerset
• Southwark, and
• West Dorset

48. What are the next steps?
How we move forward to the 2017 Census Test

49. Next steps
• Finalise the sample design
• Evaluation measures
• Setting up recruitment, systems and services

50. Your feedback

51. Your feedback please
• Questions or comments on this approach
• Anything you’d like more detail on
Comments / questions are welcome now or
Matt/Cal will be around for lunch and the rest
of the day (or cal.ghee@ons.gov.uk)