36. As noted in ‎Chapter 1, increasing use of registers and administrative data for population censuses was an important trend which has continued in the 2020 round. Only 19 countries in the UNECE region carried out a “traditional census” involving a full field enumeration, compared to 35 countries in the 2010 round. Still, if we consider also the 19 countries with a combined census that involved some element of data collection in the field, we have a total of 38 UNECE countries that conducted some sort of field operations, out of the 52 countries that conducted a census (73%). This is less than in 2010 (45 out of 54 countries, 83%), but it is still a large majority of the countries. For those countries, the field operation activities are key elements of the census operation. This chapter reports on some of these elements in respect of those countries that responded to the UNECE survey.

37. Most countries used a unique form for their enumeration. Only four countries (Belarus, Canada, Germany and Slovakia) used two different form types, long and short. A short form only collects key demographic information rather than the broader set of characteristic information collected on the longer form. Longer forms tend to be used for a sample of the population with the short form used for complete enumeration. Three countries used only short form: Switzerland, Türkiye and the United States, where since 2010 the long form is replaced by data from the American Community Survey.

38. The large majority (81%) of countries who conducted field operations used an electronic version of the questionnaire, while they were only 45% to do so in 2010.

39. Among those who did use an electronic questionnaire, 17 out of 30 (57%) did not offer a paper alternative, while they were only 5 in 2010. Thirteen countries did offer a paper alternative, and two countries used only paper questionnaires (Azerbaijan and Ireland).

40. To deliver and collect the paper (long or unique) form, the following approaches were adopted (Table 7):

		Paper questionnaire primary COLLECTION method
		Enumerators	Mail	Both mail and enumerators	Othermethods
Paper questionnaire primary DELIVERY method	Enumerators	4 countries - Azerbaijan- Bulgaria- Greece- France	2 countries - Czechia- Germany
	Mail		3 countries - Canada- Switzerland- United Kingdom
	Both mail and enumerators			2 countries - Ireland- Luxembourg
	Other methods				2 countries - Portugal- United States

41. Out of 37 responding countries that conducted a field enumeration or combined census, 31 reported some form of field operations, including 14 countries with field enumeration census and 17 countries with a combined census. By definition, countries with a wholly register-based census did not conduct any field operations, and so these are excluded from the following analyses.

42. Table 8 presents the number of countries in which some aspects of field operations applied in the 2020 census round. Overall, 70% or all countries with field operations employed in the 2020 round more than one level of field staff, against 88% in the 2010 round. In the 2010 round, all countries with field enumeration census employed more than one level of field staff, while less the two thirds did so in the 2020 round, mainly due to the increasing role of online response and reduced use of paper questionnaires.

43. The overall field operation was managed by the central statistical office in 68% of the countries, and regional or local offices managed field operations in 59% (no significant changes compared to the 2010 round). In 20 countries (54%) field operations were managed both at the national level by the central office and at the local level by regional or local office. Regional or local government agencies (such as municipalities, communes, local authorities) were involved in 57% of the countries.

44. Field operations were managed overall by the central statistical office in 68% of the countries. This is likely to reflect not only the complexity of the operation but the need to co-ordinate activity with the aim of achieving consistency in the final statistics. Regional or local offices also played a role in managing operations for their area. This was the case in 59% of the countries. In 54% of the countries field operations were managed both at the national level by the central office and at the local level by regional or local office. Regional or local government agencies (such as municipalities, communes, local authorities) were involved in 57% of the countries.

45. An address register was used in support of field operations by about half of the countries. As in the 2010 round, this practice was much more common among countries with a combined census (about three quarters of the countries) than among countries with a field enumeration census (about one quarter only).

Total . (37 countries)			Type of census
			Field enumeration (19 countries)		Combined (18 countries)
	Count	%	Count	%	Count	%
Employment of more than one level of field staff (enumerators, supervisors, etc.)	26	70	12	63	14	78
Overall field operation managed by central statistical office	25	68	11	58	14	78
Field operations managed by regional or local offices	22	59	10	53	12	67
Involvement of regional or local government agencies (such as municipalities, communes, local authorities)	21	57	10	53	11	61
Use of an address register	19	51	5	26	14	78

46. The challenge of recruiting a large field staff for enumeration is made more difficult given the need to have field coverage for all areas. Recruitment was carried out locally or regionally in 25 out of 30 reporting countries, reflecting this challenge (Table 9). In 6 of those countries recruitment was carried out also centrally. In five countries it was only carried out centrally.

47. Concerning field staff training, it was carried out at both central and regional/local level in 13 countries, only locally or regionally in 10 countries, and only centrally in 7 countries.

48. Online training is provided by 21 countries, reflecting the increased use of technology but also the likely impact of the pandemic, that made in person training more difficult given the requirements for social distancing in place at the time. Seven countries of the 21 provided online only training. In person training was still very important though, as it was provided by 20 countries. For 13 of the 20 countries training was only provided in person.

49. The length of training provided was generally short, with 17 countries providing less than a week. Nine countries provided a week, seven countries provided two weeks, and one country provided three weeks.

		Recruitment
		Centrally	Regionally/locally	Both	Total
Training	Centrally	2 Czechia Malta	4 Croatia Hungary Italy Luxembourg	1 Albania	7
	Regionally/ locally		10 Bulgaria Canada Cyprus Georgia Germany Israel North Macedonia Russian Federation Turkmenistan United States		10
	Both	3 Azerbaijan Greece Ireland	5 Belarus France Kazakhstan Poland Portugal	5 Armenia Rep. of Moldova Serbia Slovakia United Kingdom	13
	Total	5	19	6

50. As most countries carry out field operations so infrequently, it is necessary to employ for short periods of time large numbers of field staff, many of whom have limited experience of census enumeration. It is therefore important to provide field staff with manuals, materials and documentation needed for the field work, and access to form-tracking or field management systems, when possible. Results from the UNECE survey on this are presented in Table 10.

51. Almost all of the 29 reporting countries conducting field operations provide field manuals or instructions (27 countries), supplemented by maps or photographs of areas (26).

52. The availability of electronic tools as discussed in the technology section has provided a step change in the resources available to field staff. Centralised tracking is an important component of the field design in the majority of countries. Advancements in online collection instruments mean countries can be far more efficient in the allocation of field resource given the almost real time information on response information. As soon as an electronic form is submitted this can be marked as complete without delays in postage or paper forms being returned by enumerators. Field staff are given access to centralised form tracking or field managements system information in 22 countries.

53. More than half of the countries also provide field staff with summary report forms to record numbers of dwellings (19) and households (15).

	Total (out of 29 countries)	Type of census
		Field enumeration (14 countries)	Combined (15 countries)
Field manual or instruction book	27	13	14
Maps or photographs of enumeration areas	26	14	12
Access to centralized form-tracking or field management system information	22	10	12
Summary report form to record numbers of dwellings	19	10	9
Summary report form to record numbers of households	15	7	8
Summary report form to record numbers of buildings	11	7	4
Other documentation, equipment or materials	8	4	4

54. Once data has been collected by interviewers or enumerators, regardless of whether using paper questionnaires or electronically, they have to be stored safely before they are dispatched to the processing site, in order to protect data confidentiality.

55. The UNECE survey asked countries how the paper questionnaires, or the electronic data, were stored. The results are presented in Table 11. Multiple replies were possible, particularly for countries using both paper and electronic questionnaires.

56. In 19 countries (including almost all countries which did not offer a paper alternative, except Belarus) data were recorded and stored electronically and uploaded to census office.

57. When paper questionnaires were collected (even when it was not the primary way to collect the data), they were stored locally in provided secure accommodation (6 countries), stored at enumerators home (5 countries), immediately dispatched to regional/central offices (3 countries), or stored at the census managers home (2 countries).

	Total (out of 30 countries)	Type of census
		Field enumeration (15 countries)	Combined (15 countries)
Data recorded and stored electronically and uploaded to census office	19	9	10
Stored locally in specially provided secure accommodation	6	4	2
Stored by enumerators in their own homes	5	3	2
Immediately dispatched to regional or central office	3	2	1
Stored by census managers in their own homes	2	1	1
Other (please specify)	1	1	0

58. Pre-enumeration tests and rehearsals provide an opportunity to make refinements to the collection design, build delivery confidence and can identify the need for corrective action ahead of the actual field enumeration. Tests or pilots tend to be smaller in scale and earlier in the census cycle. By testing different approaches or combinations of interventions, census offices can make evidence-based decisions on their design. A rehearsal tends to be larger in scale and is in effect a dress rehearsal of the operation itself.

59. The UNECE survey collected information on whether and when pre-enumeration census tests, pilot or rehearsals were carried out (Table 12). All responding countries conducted tests, pilots or rehearsal apart from Switzerland and France where the on-going data collection operation negates the needs for tests or rehearsals.

60. The timing of this pre-enumeration activity is likely to reflect the different purposes. It was not possible to differentiate between the purposes but the 12 countries who undertook this work the year before the census were likely to have undertaken a rehearsal. Seven countries undertook this work a year before census, 14 countries two years before and 8 countries more than two years before.

61. Prior to the enumeration phases, 22 countries (73% of those reporting) also undertook pre-enumeration checks such as on addresses to be included on the census frame. In over half of the countries (13) these were carried out by both enumerators and field managers, in five countries by enumerators only, in three countries by managers only and in two countries by others.

	Total (out of 31 countries)	Type of census
		Field enumeration (15 countries)	Combined (16 countries)
Pre-enumeration census tests, pilot or rehearsals were carried out, of which…	29	14	15
Less than a year before the census	12	7	5
One year before the census	7	4	3
Two years before the census	14	7	7
More than two years before the census	8	4	4
They were NOT carried out	2	1	1
Pre-enumeration checks of the Enumeration Areas were carried out, of which…	22	13	9
By both enumerators and field managers	13	7	6
By enumerators only	5	2	3
By field managers only	3	3	0
By others	2	2	0
They were NOT carried out	8	2	6

62. A coverage post-enumeration survey (PES) can be carried out to check the coverage of the data collected through enumeration. In some cases (such as the United Kingdom) this survey is used to adjust for both under and over coverage.

63. A total of 16 countries undertook a post enumeration survey to check the coverage of the survey (Table 13). The timing of a coverage PES is important as although it needs to take place as soon after the reference day as possible (to minimise the chances of people moving or dying), it should take place after the field operation. Of the 16 countries who conducted a coverage PES, 10 undertook this less than a month after the census reference point, 5 between one and two months, and one country more than two months after. 

64. A second type of PES can also be carried out to understand the quality of the response data collected in the census. Quality PES were also undertaken by 16 countries, with 14 carrying out both coverage and quality surveys. Two countries undertook only a quality survey: Armenia and France, to better understand the response data from its rolling census. Again, there was variation in when countries carried out this type of PES with 10 countries carrying this out less than a month after the census reference point, 4 between one and two months after, and 2 more than two months after. 

65. Given the scale and complexity of the field enumeration phase, many countries see post-enumeration debriefing and evaluations as vital parts of the process. Benefits include being able to learn lessons from those aspects that worked and those that didn’t. A de-brief was carried out in only half the countries (16 out of 32), with 11 countries requiring field staff to attend as part of the job and 5 inviting field staff but not requiring attending.

	Total (out of 33 countries)	Type of census
		Field enumeration (16 countries)	Combined (17 countries)
A post-enumeration survey to check COVERAGE was carried out, of which…	16	10	6
Less than a month after the census	10	5	5
Between one and two months after the census	5	4	1
More than two months after the census	1	1	0
It was NOT carried out	17	6	11
A post-enumeration survey to check QUALITY was carried out, of which…	16	11	5
Less than a month after the census	10	6	4
Between one and two months after the census	4	3	1
More than two months after the census	2	2	0
It was NOT carried out	17	5	12
Field staff was required or invited to attend a post-enumeration DEBRIEFING, of which…	16	9	7
Required as part of job	11	7	4
Invited but not required to attend	5	2	3
Debriefing NOT carried out	16	7	9