-

-

Survey

• 100 % CAPI

14.1 %

-

-

Survey

• 100 % PAPI

20.7 %

-

-

Register,Survey

• 20.9 % CATI
• 79.1 % PAPI

1.9 %

"The reference population is persons aged 16 years or more at December 31 2003, living in private households."(Eurostat (2004). National Reference Metadata in ESS Standard for Quality Reports Structure (ESQRSSI), IS., p. 17.)

Icelandic population register

• Probability
• random
• not stratified
• one stage

Individuals

Not used

4

28-02-2004

13-05-2004

Register,Survey

• 100 % CATI

0 %

Household

Inverse of Selection Probability

"Post stratification weights are used to adjust the data to the population. The information on the population comes from the national register. The weights both adjust for nonresponse and sampling error. The post stratification weights are based on age (14 groups total, 12 groups for 16 and older and 2 groups below 16), sex and residence (2 groups). "(Eurostat (2004). National Reference Metadata in ESS Standard for Quality Reports Structure (ESQRSSI), IS., p. 7.)

See (Eurostat (2004). National Reference Metadata in ESS Standard for Quality Reports Structure (ESQRSSI), IS, pp. 7-8.)

Italian National Institute of Statistics - Socio-economic Statistics Directorate

All persons living in private households

registers of the municipalities

• Probability
• systematic
• stratified
• multi-stage

Municipality

Households

"Stratification of primary sampling units by the number of inhabitants so that the total number of inhabitants in each stratum is approximately constant (this guarantees self-weighting design in each region). Municipalities which sizes are higher than a threshold are self-representing units i.e. are strata themselves and included with certainty in the sample of PSU." (Eurostat (2004). National Reference Metadata in ESS Standard for Quality Reports Structure (ESQRSSI), IT, p. 17.)

"PSU are selected with probability proportional to their size (number of residents) by means of systematic sampling method by Madow (1949) inside each stratum. Households are selected with equal probability by systematic sampling in each selected municipality from municipality-registers." (Eurostat (2004). National Reference Metadata in ESS Standard for Quality Reports Structure (ESQRSSI), IT, pp. 18-19.)

4

-

-

Survey

• 100 % PAPI

15.9 %

Household

Inverse of Selection Probability

See (Eurostat (2004). National Reference Metadata in ESS Standard for Quality Reports Structure (ESQRSSI), IT, pp. 19-20.)

"After the non-response adjustments, the final weights were obtained applying a poststratification correction by solution of a minimisation problem under constraints, which requires the equalisation of the sampling estimates of the auxiliary variables with their respective total obtained from the population registers. The constraints are the following: For each rotational sub-group: 1) Distribution of the population by sex and fourteen 5-year age groups at NUTS I level 2) Distribution of households at NUTS II level For the entire sample: 1) Distribution of the population by sex and fourteen 5-year age groups at NUTS II level 2) Distribution of non-national population by sex and by UE and non UE distribution at NUTS I level " (Eurostat (2004). National Reference Metadata in ESS Standard for Quality Reports Structure (ESQRSSI), IT, p. 20.)

Statistics Norway

"The reference population is persons aged 16 years or more at December 31 2003 who are living outside an institution." (Eurostat (2004). National Reference Metadata in ESS Standard for Quality Reports Structure (ESQRSSI), NO., p. 32.)

• Probability
• systematic
• stratified
• multi-stage

Municipality

Individuals

"The old part of the sample, in the standard sampling frame for face-to-face interviews, the country is first divided into a number of primary sampling areas and these again are divided into 109 subpopulations, called strata. The criteria for stratification of primary sampling areas are economic classification1, population density, centrality and a prognoses classification2. The aim is to create strata, which are as homogenous as possible, but still geographically concentrated. The primary sampling units are municipalities or aggregates of municipalities. Municipalities with few inhabitants are grouped together with other municipalities to ensure that each sampling area consists of at least 7 per cent of the total number of inhabitants in the stratum the unit belongs to. In some cases small municipalities close to highly populated municipalities are put together with the large one in that region. All municipalities with more than 30 000 inhabitants and some with 25 000 to 30 000 inhabitants make separate strata. In the first stage, one primary sampling area from each stratum was selected. In the second stage, the respondents were drawn from a population register. The units in the population register were arranged by family number and personal code within the family. This was done to avoid that two or more persons within the same household was selected in the sample. The new part of the sample The primary stratification criterion for the sample is age. The design chosen implicates that age is the central criterion for representativity. The sample is drawn as a proportion p of the population within one-year groups. In addition, the population register was arranged to ensure geographical representativity. This was done by municipality and postal codes. As in the old part of the sample, the register was arranged by family number and personal code within the family before the actual drawing of units." (Eurostat (2004). National Reference Metadata in ESS Standard for Quality Reports Structure (ESQRSSI), NO., p. 6)

"The sample for EU-SILC in Norway is composed of the sample for an existing longitudinal survey established in 1997, using a specific sampling design, and a new sample with a different design in 2003. Hence two different types of sampling are used in the Norwegian EU-SILC 2004. The sample in 2003 was divided in eight rotational groups, mainly five groups in the old longitudinal sample and three groups in the new sample in 2003. In 2004 one of the eight rotational groups (from the old longitudinal survey) was deleted from the sample and a new rotational group was included in the 2004-sample. The old sample used systematically random sampling in two stages. In the first stage primary sample areas were drawn to establish a sampling frame for face-to-face interviews (Statistics Norway's standard sampling frame). Sample areas were stratified (see 2.1.3). In the second stage, respondents were drawn with a probability designed to make the sample self-weighting, i.e. all persons in the in the sampling frame have the same probability of selection (see also 2.1.5). The primary sampling units are not clustered.When drawing the new samples in 2003 and 2004, systematically random sampling in one stage was used. The systematic element stems from the stratification (see 2.1.3) and arrangement of the population register. " (Eurostat (2004). National Reference Metadata in ESS Standard for Quality Reports Structure (ESQRSSI), NO., p.5)

8

02-2004

06-2004

Register,Survey

• 0.6 % CAPI
• 99.4 % CATI

34.4 %

Household

Inverse of Selection Probability

"The probability of selection is the same for all selected respondents. Weights are only calculated to take into account non-response. Results are not calibrated to external sources. Weights are calculated by stratifying the gross sample into strata. The gross sample and net sample are stratified according to information in registers on sex, age group, education and family size. There are five categories of age: 16-24 years, 25-44 years, 45-66 years 67-79 years and 80 years and over. There are five categories of education: lower secondary and lower; upper secondary; post-secondary but non-tertiary; tertiary; missing information. There are also five categories for family size: 1, 2, 3, 4 and 5 and more persons." (Eurostat (2004). National Reference Metadata in ESS Standard for Quality Reports Structure (ESQRSSI), NO, p.8.)

"No adjustments are made, except for children's weights." (Eurostat (2004). National Reference Metadata in ESS Standard for Quality Reports Structure (ESQRSSI), NO, p.9.)

-

-

Survey

• 89.7 % CAPI
• 10.3 % PAPI

11.2 %

-

-

Survey

• 100 % CAPI

24.5 %

National Statistical Service of Greece

"The reference population is all citizens officially living at Greek territory (population de facto). Persons living in collective households and in institutions are excluded from the target population, as well as households having members diplomatic missioners." (Eurostat (2004). National Reference Metadata in ESS Standard for Quality Reports Structure (ESQRSSI), EL, p. 68.)

2001 Population Census

• Probability
• systematic
• stratified
• multi-stage

Area units

Households

"There are two levels of area stratification in the sampling design. The first level is the geographical stratification based on the partition of the total country area into thirteen (13) Regions corresponding to the European NUTS2 level. The two former major city agglomerations of Greater Athens and Greater Thessalonica constitute separate major geographical strata. The second level of stratification entails grouping Municipal/Local communes within Region by degree of urbanization, i.e., according to their population size. The scaling of urbanization was finally designed in four groups. The number of the final strata in the thirteen (13) Regions is 50. The former Greater Athens Area was divided into 31 strata on the basis of the lists of city blocks of the Municipalities that constitute it and taking into consideration socio-economic criteria. Similarly, the former Greater Thessaloniki Area was divided into 9 strata. The two Major former City Agglomerations account for about 38% of total population and for even larger percentages in certain socio-economic variables. Thus, the total number of final strata of the survey is 90." (Eurostat (2004). National Reference Metadata in ESS Standard for Quality Reports Structure (ESQRSSI), EL, p. 34.)

4

01-2004

03-2004

Survey

• 36.3 % CAPI
• 2.6 % CATI
• 60.7 % PAPI
• 0.4 % Self-administered

2.7 %

Household

Inverse of Selection Probability

"Within each design stratum, the non-response adjustment of the responding households is carried out by the inverse of the response rate, so as to “make up” for non-responding cases in that stratum." (Eurostat (2004). National Reference Metadata in ESS Standard for Quality Reports Structure (ESQRSSI), EL, p. 39.)

"Adjustment to external data involves the calibration of the household and personal weights in conjunction with external sources (Projections for population and household totals for the year 2004). This method enables the distribution of auxiliary variables, at household and individual level, to coincide with the corresponding population distribution of external data. The auxiliary variables used at household level are the household size, the tenure status and the Region (NUTS 2). Also, at personal level the auxiliary variables used are age groups (five years age groups) and gender. " (Eurostat (2004). National Reference Metadata in ESS Standard for Quality Reports Structure (ESQRSSI), EL, p. 39.)

National Statistics Institute (INE-Spain)

"The target population was members of private households residing at main family addresses, and the households themselves. (No differences between national and EU-SILC concept)." (Eurostat (2004). National Reference Metadata in ESS Standard for Quality Reports Structure (ESQRSSI), ES, p. 45.)

• Probability
• systematic
• stratified
• multi-stage

Census enumeration units

Addresses

"In each Autonomous Community [self-ruling region], first-stage units were stratified by the size of the municipality to which the census section belonged." (Eurostat (2004). National Reference Metadata in ESS Standard for Quality Reports Structure (ESQRSSI), ES, p. 11.)

"To achieve the survey objective of producing acceptably reliable estimates at both the national and at the Autonomous Community (regional) level, we selected, in wave 1 (survey 2004), a sample of 16,000 addresses spread over 2000 census sections. We distributed the sample across Autonomous Communities by allocating one part uniformly and another part in proportion to Autonomous Community size. The uniform part accounted for about 40% of sections. In the new sub-sample, census sections were selected in each stratum by a probability in proportion to size (family dwellings). In each section, addresses were selected with equal probability by systematic sampling initiated at random. This procedure produces self-weighted samples in each stratum." (Eurostat (2004). National Reference Metadata in ESS Standard for Quality Reports Structure (ESQRSSI), ES, p. 11-12.)

4

02-2004

05-2004

Survey

• 2.5 % CATI
• 95.1 % PAPI
• 2.4 % Self-administered

32.9 %

Household

See (Eurostat (2004). National Reference Metadata in ESS Standard for Quality Reports Structure (ESQRSSI), ES, pp. 13-14.)

"Adjustment for non-response is carried out by multiplying the above [design] factor by [the initial number of addresses in stratum h in rotational group t divided by the actual number of addresses in stratum h and rotational group t] to provide an estimate of the inverse probability of response in the stratum." (Eurostat (2004). National Reference Metadata in ESS Standard for Quality Reports Structure (ESQRSSI), ES, p. 14)

See (Eurostat (2004). National Reference Metadata in ESS Standard for Quality Reports Structure (ESQRSSI), ES, pp. 14-15.)

-

-

Survey

• 100 % PAPI

12.1 %

Statistics Estonia

"Persons living in collective households are included in the reference population. The share of persons who are living in collective households and who are not at the same time members of some other private household is likely to be very low." (Eurostat (2004). National Reference Metadata in ESS Standard for Quality Reports Structure (ESQRSSI), EE, p. 20.)

Statistical Population Register of Estonia

• Probability
• systematic
• stratified
• one stage

Households

Not used

"The counties (and capital Tallinn) were grouped into three strata by the population size. Hiiu County formed a separate stratum as the smallest county with the population size times smaller of the next smallest. The rest of the regions were divided into two strata – big counties and small counties." (Eurostat (2004). National Reference Metadata in ESS Standard for Quality Reports Structure (ESQRSSI), EE, p. 5.)

"For design stratified unequal probability sampling of households was used. This was achieved by selecting persons by stratified systematic sampling procedure and including their household. These persons are further called address persons. Households are regarded as sampling units although selection was made on personal level. " (Eurostat (2004). National Reference Metadata in ESS Standard for Quality Reports Structure (ESQRSSI), EE, p. 5.)

4

03-2004

06-2004

Survey

• 0.2 % CATI
• 98.6 % PAPI
• 1.2 % Self-administered

0.9 %

Household

Inverse of Selection Probability

"Non-response was compensated using the post-stratification technique. For post-stratification the counties were divided into groups that are expected to be homogeneous in respect to the measured variables of the population, i.e. in any group (post-stratum) the households are relatively similar by the measured variables and the response probability.The non-response adjustment factors were calculated as the ratio of the number of sampled households in group g to the number of responded households in group g. And finally, the non-response adjusted weights were calculated as the product of the design factor and the adjustment factor. " (Eurostat (2004). National Reference Metadata in ESS Standard for Quality Reports Structure (ESQRSSI), EE, p. 7.)

"The non-response adjusted weights were corrected in the way that the population size estimates of the survey coincide with the official population numbers published by the Statistical Office. The weights were corrected for each household using the calibration method with integrated groups defined by sex, age, residental area and level of urbanization (urban/rural area)."

(Eurostat (2004). National Reference Metadata in ESS Standard for Quality Reports Structure (ESQRSSI), EE, pp. 7-8.)

Statistics Finland

"population residing in private households (non-institutionalised persons)" (Eurostat (2004). National Reference Metadata in ESS Standard for Quality Reports Structure (ESQRSSI), FI, p. 3.)

The Population Information System maintained by the Population Register Centre of Finland

• Probability
• random
• not stratified
• one stage

Individuals

Not used

"The Finnish sampling design includes only sampling of persons, thus there is only one stage of sampling. The stratification is constructed in the first-phase master sample, not in the population." See (Eurostat (2004). National Reference Metadata in ESS Standard for Quality Reports Structure (ESQRSSI), FI, Intermediate Quality Report, p. 4)

See (Eurostat (2004). National Reference Metadata in ESS Standard for Quality Reports Structure (ESQRSSI), FI, Intermediate Quality Report, p. 3)

4

01-2004

05-2004

Register,Survey

• 2.7 % CAPI
• 97.3 % CATI

50.7 %

Individual

See (Eurostat (2004). National Reference Metadata in ESS Standard for Quality Reports Structure (ESQRSSI), FI, Intermediate Quality Report, pp. 7-9)

See (Eurostat (2004). National Reference Metadata in ESS Standard for Quality Reports Structure (ESQRSSI), FI, Intermediate Quality Report, pp. 7-9)

See (Eurostat (2004). National Reference Metadata in ESS Standard for Quality Reports Structure (ESQRSSI), FI, Intermediate Quality Report, pp. 7-9)

Register of Population Statistics of Statistics Denmark (version 1 January 2004)

• Probability
• random
• not stratified
• one stage

Individuals

Not used

-

-

Register,Survey

• 95 % CATI
• 5 % Self-administered

48.4 %

Individual

Inverse of Selection Probability

See (Eurostat (2004). National Reference Metadata in ESS Standard for Quality Reports Structure (ESQRSSI), DK, Intermediate Quality Report, Annex 1 - Weighting Procedure, pp. 13-16)

See (Eurostat (2004). National Reference Metadata in ESS Standard for Quality Reports Structure (ESQRSSI), DK, Intermediate Quality Report, Annex 1 - Weighting Procedure, pp. 16-17)

Eurostat (2004). National Reference Metadata in ESS Standard for Quality Reports Structure (ESQRSSI), DK, Intermediate Quality Report

-

-

Register,Survey

• 100 % CAPI

30.1 %