Census 2011 round (cens_11r)

National Reference Metadata in Euro SDMX Metadata Structure (ESMS)

Compiling agency: Instituto Nacional de Estatística, IP


Eurostat metadata
Reference metadata
1. Contact
2. Metadata update
3. Statistical presentation
4. Unit of measure
5. Reference Period
6. Institutional Mandate
7. Confidentiality
8. Release policy
9. Frequency of dissemination
10. Dissemination format
11. Accessibility of documentation
12. Quality management
13. Relevance
14. Accuracy
15. Timeliness and punctuality
16. Comparability
17. Coherence
18. Cost and Burden
19. Data revision
20. Statistical processing
21. Comment
Related Metadata
Annexes (including footnotes)
 



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1. Contact Top
1.1. Contact organisation

Instituto Nacional de Estatística, IP

1.2. Contact organisation unit

Gabinete dos Censos 2021

1.5. Contact mail address

Avenida António José de Almeida

1000 -043 Lisboa

Portugal


2. Metadata update Top
2.1. Metadata last certified 20/02/2014
2.2. Metadata last posted 20/02/2014
2.3. Metadata last update 25/02/2014


3. Statistical presentation Top
3.1. Data description

Not available.

3.2. Classification system

ISCO-08, NACE Rev. 2, ISOALPHA

3.3. Coverage - sector
3.4. Statistical concepts and definitions
3.4.1. Statistical concepts and definitions - Usual residence

Usual residence means the place where a person normally spends the daily period of rest, regardless of temporary absences for purposes of recreation, holidays, visits to friends and relatives, business, medical treatment or religious pilgrimage.
Persons usually resident in the place of enumeration but absent, or expected to be absent, at the time of the census for less than one year shall be considered as temporarily absent persons and thus included in the total unsually population. In contrast, persons living or expected to live outside the place of enumeration for one year or more shall not be considered temporarily absent and shall therefore be excluded from the total population. This is regardless of the length of visits that they may pay to their families from time to time.
Persons who are enumerated but do not meet the criteria for usual residence in the place of enumeration, i.e. do not live or do not expect to live in the place of enumeration for a continuous period of at least 12 months, are considered temporarily present and are therefore not counted in the total usually resident population.

3.4.2. Statistical concepts and definitions - Sex

Sex of each person.

3.4.3. Statistical concepts and definitions - Age

The age reached at the reference date (in completed years).

3.4.4. Statistical concepts and definitions - Marital status

Marital status is the (legal) conjugal status of an individual in relation to the marriage laws of the country (de jure status).
A person shall be classified according to his/her most recently acquired legal marital status at the reference date.

'Registered partnerships' are reported only by countries that have a legal framework regulating partnerships that:
(a) lead to legal conjugal obligations between two persons;
(b) are not marriages;
(c) prevent persons to commit themselves into multiple partnerships with different partners.

In countries where the legislation includes provisions for married partners to be 'legally separated', such 'legally separated' persons are classified under 'married'.

Portuguese legislation establishes/allows:

 - 16 years old as the minimum age for marriage. However, until the majority age (18 years) is required permission from parents or legal guardian;

 - Same-sex marriages, since June 2010;

 - Divorce, since 1910;

 - the legal concept of “Separation of persons and goods” which extinguishes the duties of cohabitation and support between spouses, but does not dissolve the marriage - people remain married.

 The concept of "registered partnership" does not exist in Portuguese legislation.

3.4.5. Statistical concepts and definitions - Family status

The family nucleus is defined in the narrow sense, that is as two or more persons who belong to the same household and who are related as husband and wife, as partners in a registered partnership, as partners in a consensual union, or as parent and child. Thus a family comprises a couple without children, or a couple with one or more children, or a lone parent with one or more children. This family concept limits relationships between children and adults to direct (first-degree) relationships, that is between parents and children.
Child (son/daughter) refers to a blood, step- or adopted son or daughter (regardless of age or marital status) who has usual residence in the household of at least one of the parents, and who has no partner or own children in the same household. Foster children are not included. A son or daughter who lives with a spouse, with a registered partner, with a partner in a consensual union, or with one or more own children, is not considered to be a child. A child who alternates between two households (for instance if his or her parents are divorced) shall consider the one where he or she spends the majority of the time as his or her household. Where an equal amount of time is spent with both parents the household shall be the one where the child is found at the time on census night.
The term couple shall include married couples, couples in registered partnerships, and couples who live in a consensual union.
Registered partnerships are reported only by countries that have a legal framework regulating partnerships that:
(a) lead to legal conjugal obligations between two persons;
(b) are not marriages;
(c) prevent persons to commit themselves into multiple partnerships with different partners.Two persons are considered to be partners in a 'consensual union' when they
— belong to the same household, and
— have a marriage-like relationship with each other, and
— are not married to or in a registered partnership with each other.
'Skip-generation households' (households consisting of a grandparent or grandparents and one or more grandchildren, but no parent of those grandchildren) are not included in the definition of a family.

3.4.6. Statistical concepts and definitions - Household status

Portugal applies the housekeeping concept to identify private households.

1. Housekeeping concept
According to the housekeeping concept, a private household is either:
(a) A one-person household, that is a person who lives alone in a separate housing unit or who occupies, as a lodger, a separate room (or rooms) of a housing unit but does not join with any of the other occupants of the housing unit to form part of a multiperson household as defined below; or
(b) A multiperson household, that is a group of two or more persons who combine to occupy the whole or part of a housing unit and to provide themselves with food and possibly other essentials for living. Members of the group may pool their incomes to a greater or lesser extent.

Relationships between household members were identified through a specific questionnaire: Household questionnaire. There were four questions for each person:

1 – Relationship to the Head of household;

2 - Spouse/partner identification;

3 - Father identification;

4 - Mother identification.

Households and family nucleus are generated from the information gathered in the household questionnaire. The observation of the household relationship with the head of household jointly with the identification of the spouse/partner, of the father and the mother for all persons who are thus related in the household, makes possible to build the whole identification structure for the different types of households and family nucleus.

The category 'Persons living in a private household' comprises 'Persons in a family nucleus' and 'Persons not in a family nucleus'. The category 'Persons in a family nucleus' comprises all persons who belong to a private household that contains a family nucleus of which they are a member. 'Persons not in a family nucleus' comprises all persons who either belong to a non-family household or to a family household without being member of any family nucleus in that household.
A non-family household can be a one-person household ('Living alone') or a multiperson household without any family nucleus. The category 'Not living alone' comprises persons that live either in a multiperson household without any family nucleus or in a family household without being member of any family nucleus in that household. Persons who belong to a skip-generation household and who are not member of any family nucleus in that household shall be classified in the optional category 'Persons living in a household with relative(s)'.
The term 'son/daughter' is defined as the term 'child' in the technical specifications for the topic 'Family status'. 'Husband/wife couple' means a married opposite-sex couple.
'Registered partnership' is defined as in the technical specifications for the topic 'Legal marital status'. 'Consensual union' is defined as in the technical specifications for the topic 'Family status'.
The category 'Partners' comprises 'Persons in a married couple', 'Partners in a registered partnership' and 'Partners in a consensual union'.
'Primary homeless persons' are persons living in the streets without a shelter that would fall within the scope of living quarters as defined in the technical specifications for the topic 'Type of living quarters'.

3.4.7. Statistical concepts and definitions - Current activity status

Current activity status' is the current relationship of a person to economic activity, based on a reference period of one week, which may be either a specified, recent, fixed, calendar week, or the last complete calendar week, or the last seven days prior to enumeration.
The 'currently economically active population' comprises all persons who fulfil the requirements for inclusion among the employed or the unemployed.
'Employed' persons comprise all persons aged 15 years or over who during the reference week:
(a) performed at least one hour of work for pay or profit, in cash or in kind, or
(b) were temporarily absent from a job in which they had already worked and to which they maintained a formal attachment, or from a self-employment activity.
The 'unemployed' comprise all persons aged 15 years or over who were:
(a) 'without work', that is, were not in wage employment or self-employment during the reference week; and
(b) 'currently available for work', that is, were available for wage employment or self-employment during the reference week and for two weeks after that; and
(c) 'seeking work', that is, had taken specific steps to seek wage employment or self-employment within four weeks ending with the reference week.
The category 'Currently not economically active' includes persons below the national minimum age for economic activity.
In ascribing a single activity status to each person, priority is given to the status of 'employed' in preference to 'unemployed', and to the status of 'unemployed' in preference to 'not economically active'.

3.4.8. Statistical concepts and definitions - Occupation

Occupation' refers to the type of work done in a job (that is the main tasks and duties of the work). Persons doing more than one job are allocated an occupation based on their main job, which is identified according to the time spent on the job or, if not available, to the income received.
The breakdown by occupation is available for persons aged 15 or over that were:
— employed during the reference week, or
— unemployed during the reference week, but have ever been in employment
Persons are classified according to the occupation they had during their most recent employment. The categories included in the breakdown 'occupation' correspond to the major groups of the ISCO-08 (COM) classification.
Persons under the age of 15 years, as well as persons aged 15 or over that were:
— not economically active during the reference week, or
— unemployed, never worked before (i.e. they have never been employed in their lives)
are classified under 'not applicable'.
The allocation of a person within the breakdowns of the topics 'Occupation', 'Industry' and 'Status in employment' is based on the same job.

3.4.9. Statistical concepts and definitions - Industry

Industry (branch of economic activity) is the kind of production or activity of the establishment (or similar unit) in which the job of a currently economically active person is located.
Persons doing more than one job shall be allocated an industry (branch of economic activity) based on their main job, which is to be identified according to the time spent on the job or (if not available) the income received.
The breakdown by industry is available for persons aged 15 or over that were:
— employed during the reference week, or
— unemployed during the reference week, but have ever been in employment
Persons are classified according to the industry they worked in during their most recent employment. The categories included in the breakdown 'industry' list the 21 sections of the NACE Rev. 2 classification and appropriate aggregates.
Persons under the age of 15 years, as well as persons aged 15 or over that were:
— not economically active during the reference week, or
— unemployed, and have never worked before (i.e. have never been employed in their lives)
are classified under 'not applicable'.
The allocation of a person within the breakdowns of the topics 'Occupation', 'Industry' and 'Status in employment' is based on the same job.

3.4.10. Statistical concepts and definitions - Status in employment

An 'employee' is a person who works in a 'paid employment' job, that is a job where the explicit or implicit contract of employment gives the incumbent a basic remuneration, which is independent of the revenue of the unit for which he/she works.
An 'employer' is a person who, working on his or her own account or with a small number of partners, holds a 'self-employment' job and, in this capacity, on a continuous basis (including the reference week) has engaged one or more persons to work for him/her as 'employees'.
If a person is both employer and employee, he/she shall be allocated to only one group according to the time spent on the job or (if not available) the income received.
An 'own-account worker' is a person who, working on his/her own account or with one or a few partners, holds a 'self-employment job' and has not engaged, on a continuous basis (including the reference week), any 'employees'.
A 'contributing family worker' is a person who
— holds a 'self-employment’ job in a market-oriented establishment operated by a related person, living in the same household, and
— cannot be regarded as a partner (that is an employer or own-account worker) because the degree of commitment to the operation of the establishment, in terms of working time or other factors to be determined by national circumstances, is not at a level comparable to that of the head of the establishment.
A 'member of a producers' cooperative' is a person who holds a 'self-employment' job in an establishment organised as a coop­ erative, in which each member takes part on an equal footing with other members in determining the organisation of production, sales and/or other work, the investments and the distribution of the proceeds among the members.

3.4.11. Statistical concepts and definitions - Place of work

The location of the place of work is the geographical area in which a currently employed person does his/her job.
The place of work of those mostly working at home is the same as their usual residence. The term 'working' refers to work done as an 'employed person' as defined under the topic 'Current activity status'. 'Mostly' working at home means that the person spends all or most of the time working at home, and less, or no, time in a place of work other than at home.

3.4.12. Statistical concepts and definitions - Educational attainment

'Educational attainment' refers to the highest level successfully completed in the educational system of the country where the education was received. All education which is relevant to the completion of a level is taken into account even if this was provided outside schools and universities.
Persons aged 15 years or over are classified under only one of the categories according to their educational attainment (highest completed level). Persons under the age of 15 years are classified under 'not applicable'.

3.4.13. Statistical concepts and definitions - Size of the locality

A locality is defined as a distinct population cluster, that is an area defined by population living in neighbouring or contiguous buildings. Such buildings may either:
(a) form a continuous built-up area with a clearly recognisable street formation; or
(b) though not part of such a built-up area, comprise a group of buildings to which a locally recognised place name is uniquely attached; or
(c) though not meeting either of the above two criteria, constitute a group of buildings, none of which is separated from its nearest neighbour by more than 200 metres.

3.4.14. Statistical concepts and definitions - Place of birth

Place of birth is defined as the place of usual residence of the mother at the time of the birth, or, if not available, as the place in which the birth took place.
Information on the country of birth is based on the international boundaries existing on 1 January 2011. 'EU Member State', in particular, means a country that is a member of the European Union on 1 January 2011. The list of countries in the breakdown 'country/place of birth' serves only for statistical purposes.
For reporting countries that are EU Member States, the sub-category under the category 'other EU Member State' that refers to their Member State does not apply. For reporting countries that are not EU Member States, the category 'Other EU Member State' shall be read as 'EU Member State'.
The category 'Information not classifiable according to current borders' covers those persons whose country of birth existed at the time of the birth, but no longer exists at the time of the census, and who cannot be allocated uniquely to one country existing at the time of the census, i.e. according to current borders.
The category 'outside any country' covers persons for whom the usual residence of the mother at the time of the birth is not known and who where born outside the borders of any country, for example at sea or in the air.

3.4.15. Statistical concepts and definitions - Country of citizenship

Citizenship is defined as the particular legal bond between an individual and his/her State, acquired by birth or naturalisation, whether by declaration, option, marriage or other means according to the national legislation.
A person with two or more citizenships is allocated to only one country of citizenship, to be determined in the following order of precedence:
1. reporting country; or
2. if the person does not have the citizenship of the reporting country: other EU Member State; 3. if the person does not have the citizenship of another EU Member State: other country outside the European Union.
'EU Member State' means a country that is a member of the European Union on 1 January 2011. The list of countries in the breakdown 'Country of citizenship' shall only apply for statistical purposes.
For reporting countries that are EU Member States, the sub-category of the category 'citizenship not of reporting country, but other EU Member State' that refers to their Member State does not apply. For reporting countries that are not EU Member States, the category 'citizenship not of reporting country, but other EU Member State' shall be changed to 'citizenship of an EU Member State'.
Persons who are neither citizens of any country nor stateless and who have some but not all of the rights and duties associated with citizenship shall be classified under 'recognised non-citizens'.

3.4.16. Statistical concepts and definitions - Year of arrival in the country

The year of arrival is the calendar year in which a person most recently established usual residence in the country. The data for 2011 refer to the time span between 1 January 2011 and the reference date.

3.4.17. Statistical concepts and definitions - Residence one year before

This indicates the relationship between the current place of usual residence and the place of usual residence one year prior to the census. Children under one year of age are classified under 'Not applicable'.
For all persons that have changed their usual residence more than once within the year prior to the reference date, the previous place of usual residence is the last usual residence from which they moved to their current place of usual residence.

3.4.18. Statistical concepts and definitions - Housing arrangements

The topic 'Housing arrangements' covers the whole population and refers to the type of housing in which a person usually resides at the time of the census. This covers all persons who are usual residents in different types of living quarters, or who do not have a usual residence and stay temporarily in some type of living quarters, or who are roofless, sleeping rough or in emergency shelters, when the census is taken.
Occupants are persons with their usual residence in the places listed in the respective category.
'Conventional dwellings' are structurally separate and independent premises at fixed locations which are designed for permanent human habitation and are, at the reference date, either used as a residence, or vacant, or reserved for seasonal or secondary use.
'Separate' means surrounded by walls and covered by a roof or ceiling so that one or more persons can isolate themselves. 'Independent' means having direct access from a street or a staircase, passage, gallery or grounds.
'Other housing units' are huts, cabins, shacks, shanties, caravans, houseboats, barns, mills, caves or any other shelter used for human habitation at the time of the census, irrespective if it was designed for human habitation.
'Collective living quarters' are premises which are designed for habitation by large groups of individuals or several households and which are used as the usual residence of at least one person at the time of the census.
'Occupied conventional dwellings', 'other housing units' and 'collective living quarters' together represent'‘living quarters'. Any 'living quarter' must be the usual residence of at least one person.
The sum of occupied conventional dwellings and other housing units represents 'housing units'.
The homeless (persons who are not usual residents in any living quarter category) can be persons living in the streets without a shelter that would fall within the scope of living quarters (primary homelessness) or persons moving frequently between temporary accommodation (secondary homelessness).

3.4.19. Statistical concepts and definitions - Type of family nucleus

The family nucleus is defined in the narrow sense, that is as two or more persons who belong to the same household and who are related as husband and wife, as partners in a registered partnership, as partners in a consensual union, or as parent and child. Thus a family comprises a couple without children, or a couple with one or more children, or a lone parent with one or more children. This family concept limits relationships between children and adults to direct (first-degree) relationships, that is between parents and children.
Child (son/daughter) refers to a blood, step- or adopted son or daughter (regardless of age or marital status) who has usual residence in the household of at least one of the parents, and who has no partner or own children in the same household. Foster children are not included. A son or daughter who lives with a spouse, with a registered partner, with a partner in a consensual union, or with one or more own children, is not considered to be a child. A child who alternates between two households (for instance if his or her parents are divorced) shall consider the one where he or she spends the majority of the time as his or her household. Where an equal amount of time is spent with both parents the household shall be the one where the child is found at the time on census night.
The term couple shall include married couples, couples in registered partnerships, and couples who live in a consensual union.
Registered partnerships are reported only by countries that have a legal framework regulating partnerships that:
(a) lead to legal conjugal obligations between two persons;
(b) are not marriages;
(c) prevent persons to commit themselves into multiple partnerships with different partners.
Two persons are considered to be partners in a 'consensual union' when they
— belong to the same household, and
— have a marriage-like relationship with each other, and
— are not married to or in a registered partnership with each other.
'Skip-generation households' (households consisting of a grandparent or grandparents and one or more grandchildren, but no parent of those grandchildren) are not included in the definition of a family.

3.4.20. Statistical concepts and definitions - Size of family nucleus

The family nucleus is defined in the narrow sense, that is as two or more persons who belong to the same household and who are related as husband and wife, as partners in a registered partnership, as partners in a consensual union, or as parent and child. Thus a family comprises a couple without children, or a couple with one or more children, or a lone parent with one or more children. This family concept limits relationships between children and adults to direct (first-degree) relationships, that is between parents and children.
Child (son/daughter) refers to a blood, step- or adopted son or daughter (regardless of age or marital status) who has usual residence in the household of at least one of the parents, and who has no partner or own children in the same household. Foster children are not included. A son or daughter who lives with a spouse, with a registered partner, with a partner in a consensual union, or with one or more own children, is not considered to be a child. A child who alternates between two households (for instance if his or her parents are divorced) shall consider the one where he or she spends the majority of the time as his or her household. Where an equal amount of time is spent with both parents the household shall be the one where the child is found at the time on census night.
The term couple shall include married couples, couples in registered partnerships, and couples who live in a consensual union.
Registered partnerships are reported only by countries that have a legal framework regulating partnerships that:
(a) lead to legal conjugal obligations between two persons;
(b) are not marriages;
(c) prevent persons to commit themselves into multiple partnerships with different partners.
Two persons are considered to be partners in a 'consensual union' when they
— belong to the same household, and
— have a marriage-like relationship with each other, and
— are not married to or in a registered partnership with each other.
'Skip-generation households' (households consisting of a grandparent or grandparents and one or more grandchildren, but no parent of those grandchildren) are not included in the definition of a family.

3.4.21. Statistical concepts and definitions - Type of private household

Private households may be defined according to the 'housekeeping concept' , or, if this is not possible, Member States may apply the 'household-dwelling' concept.
1. Housekeeping concept
According to the housekeeping concept, a private household is either:
(a) A one-person household, that is a person who lives alone in a separate housing unit or who occupies, as a lodger, a separate room (or rooms) of a housing unit but does not join with any of the other occupants of the housing unit to form part of a multiperson household as defined below; or
(b) A multiperson household, that is a group of two or more persons who combine to occupy the whole or part of a housing unit and to provide themselves with food and possibly other essentials for living. Members of the group may pool their incomes to a greater or lesser extent.
2. Household-dwelling concept
The household-dwelling concept considers all persons living in a housing unit to be members of the same household, such that there is one household per occupied housing unit. In the household dwelling concept, then, the number of occupied housing units and the number of households occupying them is equal, and the locations of the housing units and house­ holds are identical.
The category 'Persons living in a private household' comprises 'Persons in a family nucleus' and 'Persons not in a family nucleus'. The category 'Persons in a family nucleus' comprises all persons who belong to a private household that contains a family nucleus of which they are a member. 'Persons not in a family nucleus' comprises all persons who either belong to a non-family household or to a family household without being member of any family nucleus in that household.
A non-family household can be a one-person household ('Living alone') or a multiperson household without any family nucleus. The category 'Not living alone' comprises persons that live either in a multiperson household without any family nucleus or in a family household without being member of any family nucleus in that household. Persons who belong to a skip-generation household and who are not member of any family nucleus in that household shall be classified in the optional category 'Persons living in a household with relative(s)'.
The term 'son/daughter' is defined as the term 'child' in the technical specifications for the topic 'Family status'. 'Husband/wife couple' means a married opposite-sex couple.
'Registered partnership' is defined as in the technical specifications for the topic 'Legal marital status'. 'Consensual union' is defined as in the technical specifications for the topic 'Family status'.
The category 'Partners' comprises 'Persons in a married couple', 'Partners in a registered partnership' and 'Partners in a consensual union'.
'Primary homeless persons' are persons living in the streets without a shelter that would fall within the scope of living quarters as defined in the technical specifications for the topic 'Type of living quarters'.

3.4.22. Statistical concepts and definitions - Size of private household

Private households may be defined according to the 'housekeeping concept' , or, if this is not possible, Member States may apply the 'household-dwelling' concept.
1. Housekeeping concept
According to the housekeeping concept, a private household is either:
(a) A one-person household, that is a person who lives alone in a separate housing unit or who occupies, as a lodger, a separate room (or rooms) of a housing unit but does not join with any of the other occupants of the housing unit to form part of a multiperson household as defined below; or
(b) A multiperson household, that is a group of two or more persons who combine to occupy the whole or part of a housing unit and to provide themselves with food and possibly other essentials for living. Members of the group may pool their incomes to a greater or lesser extent.
2. Household-dwelling concept
The household-dwelling concept considers all persons living in a housing unit to be members of the same household, such that there is one household per occupied housing unit. In the household dwelling concept, then, the number of occupied housing units and the number of households occupying them is equal, and the locations of the housing units and house­ holds are identical.
The category 'Persons living in a private household' comprises 'Persons in a family nucleus' and 'Persons not in a family nucleus'. The category 'Persons in a family nucleus' comprises all persons who belong to a private household that contains a family nucleus of which they are a member. 'Persons not in a family nucleus' comprises all persons who either belong to a non-family household or to a family household without being member of any family nucleus in that household.
A non-family household can be a one-person household ('Living alone') or a multiperson household without any family nucleus. The category 'Not living alone' comprises persons that live either in a multiperson household without any family nucleus or in a family household without being member of any family nucleus in that household. Persons who belong to a skip-generation household and who are not member of any family nucleus in that household shall be classified in the optional category 'Persons living in a household with relative(s)'.
The term 'son/daughter' is defined as the term 'child' in the technical specifications for the topic 'Family status'. 'Husband/wife couple' means a married opposite-sex couple.
'Registered partnership' is defined as in the technical specifications for the topic 'Legal marital status'. 'Consensual union' is defined as in the technical specifications for the topic 'Family status'.
The category 'Partners' comprises 'Persons in a married couple', 'Partners in a registered partnership' and 'Partners in a consensual union'.
'Primary homeless persons' are persons living in the streets without a shelter that would fall within the scope of living quarters as defined in the technical specifications for the topic 'Type of living quarters'.

3.4.23. Statistical concepts and definitions - Tenure status of household

The topic 'Tenure status of households' refers to the arrangements under which a private household occupies all or part of a housing unit.
Households that are in the process of paying off a mortgage on the housing unit in which they live or purchasing their housing unit over time under other financial arrangementsare classified under 'Households of which at least one member is the owner of the housing unit'.
Households of which at least one member is the owner of the housing unit and at least one member tenant of all or part of the housing unit are classified under category 'Households of which at least one member is the owner of the housing unit'.

3.4.24. Statistical concepts and definitions - Type of living quarter

'Conventional dwellings' are structurally separate and independent premises at fixed locations which are designed for permanent human habitation and are, at the reference date, either used as a residence, or vacant, or reserved for seasonal or secondary use.
'Separate' means surrounded by walls and covered by a roof or ceiling so that one or more persons can isolate themselves. 'Independent' means having direct access from a street or a staircase, passage, gallery or grounds.
'Other housing units' are huts, cabins, shacks, shanties, caravans, houseboats, barns, mills, caves or any other shelter used for human habitation at the time of the census, irrespective if it was designed for human habitation.
'Collective living quarters' are premises which are designed for habitation by large groups of individuals or several households and which are used as the usual residence of at least one person at the time of the census.
'Occupied conventional dwellings', 'other housing units' and 'collective living quarters' together represent'‘living quarters'. Any 'living quarter' must be the usual residence of at least one person.

3.4.25. Statistical concepts and definitions - Occupancy status

'Occupied conventional dwellings' are conventional dwellings which are the usual residence of one or more persons at the time of the census. 'Unoccupied conventional dwellings' are conventional dwellings which are not the usual residence of any person at the time of the census.
Conventional dwellings with persons present but not included in the census are classified under the category 'Dwellings reserved for seasonal or secondary use'.

3.4.26. Statistical concepts and definitions - Type of ownership

The topic 'Type of ownership' refers to the ownership of the dwelling and not to that of the land on which the dwelling stands.
'Owner-occupied dwellings' are those where at least one occupant of the dwelling owns parts or the whole of the dwelling. 'Cooperative ownership' refers to ownership within the framework of a housing cooperative.
'Rented dwellings' are those where at least one occupant pays a rent for the occupation of the dwelling, and where no occupant owns parts or the whole of the dwelling.

3.4.27. Statistical concepts and definitions - Number of occupants

The number of occupants of a housing unit is the number of people for whom the housing unit is the usual residence.

3.4.28. Statistical concepts and definitions - Useful floor space

Useful floor space is defined as the floor space measured inside the outer walls excluding non-habitable cellars and attics and, in multi-dwelling buildings, all common spaces; or the total floor space of rooms falling under the concept of 'room'.

3.4.29. Statistical concepts and definitions - Number of rooms

A 'room' is defined as a space in a housing unit enclosed by walls reaching from the floor to the ceiling or roof, of a size large enough to hold a bed for an adult (4 square metres at least) and at least 2 metres high over the major area of the ceiling.

3.4.30. Statistical concepts and definitions - Density standard (floor space)

The topic ‘Density standard’ relates the useful floor space in square metres or the number of rooms to the number of occupants, as specified under the topic 'Number of occupants'.
Data report on the density standard measured by the 'useful floor space', or, if not possible, by the 'number of rooms'.

3.4.31. Statistical concepts and definitions - Density standard (number of rooms)

The topic ‘Density standard’ relates the useful floor space in square metres or the number of rooms to the number of occupants, as specified under the topic 'Number of occupants'.
Data report on the density standard measured by the 'useful floor space', or, if not possible, by the 'number of rooms'.

3.4.32. Statistical concepts and definitions - Water supply system

Water supply sytem means piped water in the housing unit from a community scheme or from a private source.

3.4.33. Statistical concepts and definitions - Toilet facilities

Toilet facilities means a flush toilet in the housing unit.

3.4.34. Statistical concepts and definitions - Bathing facilities

A bathing facility is any facility designed to wash the whole body and includes shower facilities, which has fixed connections to both a water supply and a sewage disposal system.

3.4.35. Statistical concepts and definitions - Type of heating

A housing unit is considered as centrally heated if heating is provided either from a community heating centre or from an installation built in the building or in the housing unit, established for heating purposes, without regard to the source of energy.

3.4.36. Statistical concepts and definitions - Type of building

The topic 'Dwellings by type of building' refers to the number of dwellings in the building in which the dwelling is placed.

3.4.37. Statistical concepts and definitions - Period of construction

The topic 'Dwellings by period of construction' refers to the year when the building in which the dwelling is placed was completed.

3.5. Statistical unit

The EU programme for the 2011 population and housing censuses include data on persons, private households, family nuclei, conventional dwellings and living quarters

3.6. Statistical population

Persons enumerated in the 2011 census are those who were usually resident in the territory of the reporting country at the census reference date. Usual residence means the place where a person normally spends the daily period of rest, regardless of temporary absences for purposes of recreation, holidays, visits to friends and relatives, business, medical treatment or religious pilgrimage

3.7. Reference area

Data are available at different levels of geographical detail: national, NUTS2, NUTS3 and local administrative units (LAU2)

3.8. Coverage - Time

Data refer to the situation in the reporting country at the census reference date (see item 5)

3.9. Base period


4. Unit of measure Top

Counts of statistical units


5. Reference Period Top
21/03/2011


6. Institutional Mandate Top
6.1. Institutional Mandate - legal acts and other agreements

Common reminder of EU legislation

6.1.1. Bodies responsible

The 2011 Census is governed by specific legislation - Decree-Law 226/2009 of 14 September 2009 defining the powers and responsibilities of the various parties involved in the census operation.

    The Temporary 2011 Census Board (Secção Eventual para Acompanhamento dos Censos, 2011 – SEAC2011) of the Higher Statistical Council is the main body responsible for steering and coordinating the 2011 Census;

    The National Statistical Institute (INE, IP) is responsible for devising and administering census-taking activities at central, regional and local level;

    The Azores Regional Statistical Service and the Madeira Regional Statistical Directorate are responsible for coordinating and implementing the census operation in their respective Autonomous Regions;

    The Municipal Chambers are responsible for organising, coordinating and monitoring census tasks within their area of jurisdiction;

    The Parish Councils ensure performance of census-taking operations within their geographical areas.

6.2. Institutional Mandate - data sharing

Not available.


7. Confidentiality Top
7.1. Confidentiality - policy

Article 6 of Law No 22/2008 of 13 May 2008, laying down the principles, rules and structure of the national statistical system, refers to the principle of statistical confidentiality and states that all individual data concerning individuals or groups gathered by the statistical authorities are confidential in nature and may not be disseminated in such a way as to permit direct or indirect identification.

Article 20, "Confidentiality", of Decree-Law No 226/2009 of 14 September 2009 (which lays down the rules to be obeyed by the 2011 Census) states that individual statistical data collected in the framework of the 2011 Census are subject to the principle of statistical confidentiality, constituting a professional secret for all persons who are involved in these statistical operations and have awareness of those data pursuant to Article 6 of Law No 22/2008 of 13 May 2008.

7.2. Confidentiality - data treatment

In Portugal, the dissemination programme for the 2011 Census is approved by the Higher Statistical Council. This programme provide over 100 tables showing the data broken down to parish level: these tables are not subject to the statistical confidentiality rules for data processing.

Some procedures approved internally are also followed for requests outside the dissemination programme: these limit the number of variables that can be cross-classified, taking account of the geographical breakdown. The greater the geographical breakdown, the smaller the number of variables that can be cross-classified. A maximum of eight variables can be cross-classified at national geographical level, and a maximum of three at parish geographical level.


8. Release policy Top
8.1. Release calendar

Data are made available 27 months after the end of the reference period (March 2014)

8.2. Release calendar access
8.3. Release policy - user access

Conditions of accessibility to statistical information:

Access to official statistics is free of charge, unless further processing of the information is required;

Access to statistical information is guaranteed to all users simultaneously;

The Official Statistics Portal (www.ine.pt) is the principal means of dissemination of statistical information: all official statistics are disseminated here first hand.

The official statistical information disseminated is accompanied by the relevant metadata.

For the 2011 census a dissemination programme was developed around three main objectives:

 - Simplification of access to Census information, with priority given to making data available on the Official Statistics Portal;

 - Rapidity in availability of the information - the results of the2011 Census were made available in three stages: Preliminary results, Provisional results and Definitive results;

- Increase in the range of dissemination products on offer – focus on diversifying dissemination products.


9. Frequency of dissemination Top

Data on population and housing censuses are disseminated every decade


10. Dissemination format Top
10.1. Dissemination format - News release

10 press releases were issued containing exclusive information about the 2011 Census:

Censos 2011 – Resultados Preliminares - 30 junho de 2011

Censos 2011 – Parque habitacional (Resultados pré-provisórios) 8 novembro de 2011

Censos 2011 – Resultados Provisórios – 7 dezembro de 2011

Censos 2011 – Resultados Pré-definitivos – 3 fevereiro de 2012

Censos 2011 – Resultados definitivos - População cresce 2% na última década – 20 novembro 2012

Censos 2011 - População estrangeira cresceu 70% na última década - 17 dezembro de 2012

Censos 2011 – O Perfil do Pai que vive com os filhos – 18 março de 2013

Censos 2011 – Comunidade Brasileira é a maior comunidade estrangeira em Portugal - 19 abril de 2013

Censos 2011 – O retrato da Mãe que vive com os Filhos - 5 maio 2013

Censos 2011 - Como evoluíram as famílias em Portugal? – 20 novembro de 2013



Annexes:
Censos 2011 – Resultados Preliminares
Censos 2011 – Parque habitacional (resultados pré-provisórios)
Censos 2011 - Resultados provisórios
Censos 2011 – Resultados Pré-definitivos
Censos 2011 – Resultados definitivos - População cresce 2% na última década
Censos 2011 - População estrangeira cresceu 70% na última década
Censos 2011 – O Perfil do Pai que vive com os filhos
Censos 2011 – Comunidade Brasileira é a maior comunidade estrangeira em Portugal
Censos 2011 – O retrato da Mãe que vive com os Filhos
Censos 2011 - Como evoluíram as famílias em Portugal
10.2. Dissemination format - Publications

Eight publications were issued containing the results of the 2011 Census (1 national and 7 regional - NUTSII). In addition to the traditional tables and statistical diagrams, the publications included a data analysis component.

A publication containing the metadata associated with the 2011 Census was also issued.

All of the publications are available online and in hard copy.

List of publications:

Censos 2011 – Resultados definitivos – Portugal, Instituto Nacional de Estatística, IP, Lisboa, Portugal 2012

Censos 2011 – Resultados definitivos – Região Norte, Instituto Nacional de Estatística, IP, Lisboa, Portugal 2012

Censos 2011 – Resultados definitivos – Região Centro, Instituto Nacional de Estatística, IP, Lisboa Portugal 2012

Censos 2011 – Resultados definitivos – Região de Lisboa, Instituto Nacional de Estatística, IP, Lisboa Portugal 2012

Censos 2011 – Resultados definitivos – Região Alentejo, Instituto Nacional de Estatística, IP, Lisboa, Portugal 2012

Censos 2011 – Resultados definitivos – Região Algarve, Instituto Nacional de Estatística, IP, Lisboa, Portugal 2012

Censos 2011 – Resultados definitivos – Região da Madeira, Instituto Nacional de Estatística, IP, Lisboa, Portugal 2012

Censos 2011 – Resultados definitivos – Região dos Açores, Instituto Nacional de Estatística, IP, Lisboa, Portugal 2012

Censos 2011 – Preparação, metodologia e conceitos – Instituto Nacional de Estatística, IP, Lisboa, Portugal 2013



Annexes:
Censos 2011 – Resultados definitivos – Portugal
Censos 2011 – Resultados definitivos – Região Norte
Censos 2011 – Resultados definitivos – Região Centro
Censos 2011 – Resultados definitivos – Região de Lisboa
Censos 2011 – Resultados definitivos – Região Alentejo
Censos 2011 – Resultados definitivos – Região Algarve
Censos 2011 – Resultados definitivos – Região da Madeira
Censos 2011 – Resultados definitivos – Região dos Açores
Censos 2011 – Preparação, metodologia e conceitos
10.3. Dissemination format - online database

Information on the 2011 Census is available on the INE's Official Statistics Portal (www.ine.pt), in an online database containing over 400 statistical indicators down to Parish geographical level.



Annexes:
Base de dados online
10.4. Dissemination format - microdata access

The 2011 Census provides a sample of anonymised microdata made up of randomly selected records of 5% of the resident individuals. Given that the microdata consist of individualised information files, the sample is anonymised and the data processed in such a way as to guarantee not only their confidentiality but also their quality. This sample is only available to accredited researchers and as part of the IPUMS project.

10.5. Dissemination format - other

BGRI Censos 2011 - This application enables users to consult the Geographical Information Referencing Database  (Base Geográfica de Referenciação da Informação – BGRI 2011) and download any territorial unit with associated statistical information. The statistical indicators available are the following: Resident population, present population, households, dwellings and buildings.

2011 Census summary file - consists of aggregators for a series of predefined variables at the smallest geographical level (statistical subsection). This enables users to map these variables.



Annexes:
Censos 2011 - BGRI
Censos 2011 - Ficheiro Síntese


11. Accessibility of documentation Top
11.1. Documentation on methodology

Action programme for the 2011 Census - document providing a framework for the census operation and setting out the objectives, guidelines, variables to observe and a summary of the main activities to be combined for the performance of the census.

Methodological document for the2011 Census - document describing the methodological aspects of the census-taking operation.



Annexes:
Plano de ação para os Censos 2011
Documento metodológico dos Censos 2011
11.2. Quality management - documentation

Censos 2011 - Programa de controlo e avaliação da qualidade - Controlo do processo produtivo

Censos 2011 - Inquérito de qualidade: metodologia e resultados



Annexes:
Censos 2011 - Programa de controlo e avaliação da qualidade - Processo produtivo
Censos 2011 - Inquérito de Qualidade


12. Quality management Top
12.1. Quality assurance

The performance of operations for the 2011 Census was accompanied by a far-reaching quality control and assessment programme. This programme concentrated on the following two areas:

 - Quality control in the productive process;

- Performance of a quality survey.

Quality control in the productive process included the implementation of mechanisms to verify and monitor key points throughout the productive process that had the potential to compromise the quality of the results of the censuses.

The quality of the results was assessed by means of a quality survey, conducted independently at the end of the data-gathering operation with the aim of quantifying the errors in the coverage and content of the census-taking operation.

In order to ensure greater independence and transparency in the assessment of the 2011 Census, the INE, IP received support from higher education institutions: ISCTE - Lisbon University Institute, for the quality control in the productive process, and ISEGI – NOVA School of Statistics and Information Management for the quality survey.

12.2. Quality management - assessment
12.2.1. Coverage assessment

The methodology associated with the control and assessment of the productive process concentrated on identifying and monitoring key processes to guarantee effective performance of the work in the field and the quality of the information collected. The following key processes for the control of quality assessment in the productive process are of particular note:

1) Human resources

2) Fieldwork - distribution and collection

3) Treatment of data

The strategic guidelines associated with each of these processes were developed by making use of the Balanced Scorecard tool. This tool makes it possible to realise the vision and strategic objectives associated with a given process and at the same time define measurable monitoring indicators.

The use of a fieldwork monitoring system (Sistema de Controlo de Trabalho de Campo - SCTC) made it possible to systematise and monitor all of the processes related to the management and monitoring of human resources and fieldwork at national, regional and local levels.

 1 – Human resources

Ensure that each of the levels of the executive structure involved in the process fulfils the requirements and has the capacity needed for correct performance of its tasks: human resources are the key to correct implementation of the procedures.

Main measures implemented:

    Definition of profiles in accordance with specified powers and responsibilities

    Selection of candidates via pre-selection tests

    Training programme and supporting documentation

    Implementation of a technical evaluation sheet

 2 - Fieldwork

In addition to the monitoring indicators related to compliance with distribution and collection deadlines, a procedure enabling individualised monitoring of census enumerators' work was implemented in the form of a re-survey of a sample of dwellings (5%), based on a second observation by the coordinator and consisting of a set of three questions.

A system of alert indicators was implemented, constituting a tool based on the anticipated values for the statistical units to be observed in the 2011 Census. Implementation of that system made it possible to obtain information on possible anomalies in the collection process and establish their probable cause. It was thus possible to monitor the distribution and collection process in real time, which made it possible to make adjustments or implement corrective measures with a view to guaranteeing the quality principles that must guide the performance of a census-taking operation. The system of alert indicators was based on the anticipated values calculated for the "dwellings" and "persons" statistical units with geographical breakdown at parish level. Whenever deviations were found from the anticipated values, the situation was investigated and the corresponding explanation provided.

Main measures implemented:

    Performance of individual controls

    Preparation and assessment of progress reports

    Assessment of files and maps used to monitor fieldwork

    Assessment of maps used to monitor deviations

    Alert map (identification of areas in accordance with the risk/difficulty of performing the operation)

 3) Treatment of data

Various quality control and monitoring indicators were implemented at the various stages of the process (preparation of questionnaires, optical recognition, validation, coding, etc.)

Main measures implemented:

    Assessment of control maps (application - workflow)

    Selection of sample (2%) for checking at some stages of the process

12.2.2. Post-enumeration survey(s)

The 2011 Census Quality Survey was an autonomous and independent statistical operation during which some of the statistical units observed in the 2011 Census were re-surveyed. The main aims of the Quality Survey were to assess errors in coverage and in content for a set of variables.

The 2011 Census Quality Survey was carried out once the collection of census data was complete and made use of probability samples from parishes, statistical sections and housing units, corresponding to 1.8 % of the total number of dwellings covered. It covered the whole of the national territory and was representative at NUTS II level for a set of variables. Data were collected exclusively via face-to-face interviews carried out by teams other than those used for the 2011 Census. The same questionnaires were used, although the number of questions was restricted to those that are mandatory pursuant to the EU regulations.

The methodology and results of the Quality Survey are contained in the publication :Censos 2011 – Inquérito de Qualidade: metodologia e resultados –  (2011 Censuses - Quality survey: methodology and results) Portugal, Instituto Nacional de Estatística, IP, Lisbon, Portugal 2013



Annexes:
Censos 2011 - Inquérito de qualidade: metodologia e resultados


13. Relevance Top
13.1. Relevance - User Needs

The census data disseminated by Eurostat are addressed to policy makers, researchers, media and the general public.

13.2. Relevance - User Satisfaction

No user satisfaction surveys are carried out. User inquiries are handled by the Eurostat User Support service.

13.3. Completeness

Depends on the availability of data transmitted by the National Statistical Institutes.


14. Accuracy Top
14.1. Accuracy - overall
14.1.1. Accuracy overall - Usual residence

There are no particular reasons for data unreliability for this topic

14.1.2. Accuracy overall - Sex

There are no particular reasons for data unreliability for this topic

14.1.3. Accuracy overall - Age

There are no particular reasons for data unreliability for this topic

14.1.4. Accuracy overall - Marital status

There are no particular reasons for data unreliability for this topic

14.1.5. Accuracy overall - Family status

There are no particular reasons for data unreliability for this topic

14.1.6. Accuracy overall - Household status

There are no particular reasons for data unreliability for this topic

14.1.7. Accuracy overall - Current activity status

There are no particular reasons for data unreliability for this topic

14.1.8. Accuracy overall - Occupation

There are no particular reasons for data unreliability for this topic

14.1.9. Accuracy overall - Industry

There are no particular reasons for data unreliability for this topic

14.1.10. Accuracy overall - Status in employment

There are no particular reasons for data unreliability for this topic

14.1.11. Accuracy overall - Place of work

There are no particular reasons for data unreliability for this topic

14.1.12. Accuracy overall - Educational attainment

There are no particular reasons for data unreliability for this topic

14.1.13. Accuracy overall - Size of the locality

There are no particular reasons for data unreliability for this topic

14.1.14. Accuracy overall - Place of birth

There are no particular reasons for data unreliability for this topic

14.1.15. Accuracy overall - Country of citizenship

There are no particular reasons for data unreliability for this topic

14.1.16. Accuracy overall - Year of arrival in the country

There are no particular reasons for data unreliability for this topic

14.1.17. Accuracy overall - Residence one year before

There are no particular reasons for data unreliability for this topic

14.1.18. Accuracy overall - Housing arrangements

There are no particular reasons for data unreliability for this topic

14.1.19. Accuracy overall - Type of family nucleus

There are no particular reasons for data unreliability for this topic

14.1.20. Accuracy overall - Size of family nucleus

There are no particular reasons for data unreliability for this topic

14.1.21. Accuracy overall - Type of private household

There are no particular reasons for data unreliability for this topic

14.1.22. Accuracy overall - Size of private household

There are no particular reasons for data unreliability for this topic

14.1.23. Accuracy overall - Tenure status of household

There are no particular reasons for data unreliability for this topic

14.1.24. Accuracy overall - Type of living quarter

There are no particular reasons for data unreliability for this topic

14.1.25. Accuracy overall - Occupancy status

There are no particular reasons for data unreliability for this topic

14.1.26. Accuracy overall - Type of ownership

There are no particular reasons for data unreliability for this topic

14.1.27. Accuracy overall - Number of occupants

There are no particular reasons for data unreliability for this topic

14.1.28. Accuracy overall - Useful floor space

There are no particular reasons for data unreliability for this topic

14.1.29. Accuracy overall - Number of rooms

There are no particular reasons for data unreliability for this topic

14.1.30. Accuracy overall - Density standard (floor space)

There are no particular reasons for data unreliability for this topic

14.1.31. Accuracy overall - Density standard (number of rooms)

There are no particular reasons for data unreliability for this topic

14.1.32. Accuracy overall - Water supply system

There are no particular reasons for data unreliability for this topic

14.1.33. Accuracy overall - Toilet facilities

There are no particular reasons for data unreliability for this topic

14.1.34. Accuracy overall - Bathing facilities

There are no particular reasons for data unreliability for this topic

14.1.35. Overall accuracy - Type of heating

There are no particular reasons for data unreliability for this topic

14.1.36. Overall accuracy - Type of building

There are no particular reasons for data unreliability for this topic

14.1.37. Overall accuracy - Period of construction

There are no particular reasons for data unreliability for this topic

14.2. Sampling error
14.3. Non-sampling error


15. Timeliness and punctuality Top
15.1. Timeliness

All hypercubes (HC01 to HC60) were available by 26 November 2013.

15.2. Punctuality


16. Comparability Top
16.1. Comparability - geographical

There are no national practices which could impair the EU-wide comparability.

16.2. Comparability - over time


17. Coherence Top
17.1. Coherence - cross domain

Figures provided by the National Statistical Institutes in the framework of the 2011 Population and Housing Census may differ from those transmitted in other statistical domains due to the cross domain differences in definitions and methodologies used.  For additional information please see metadata specific to each domain.

17.2. Coherence - internal

Internal coherence is assured by regulations defining breakdowns and definitions of topics (Regulation (EC) No 1201/2009, Regulation (EU) No 519/2010, Regulation (EU) No 1151/2010)


18. Cost and Burden Top
Restricted from publication


19. Data revision Top
19.1. Data revision - policy

Under the dissemination plan for the 2011 Census, the results were made available in three stages:

• Preliminary results, available in June 2011

• Provisional results, available in December 2011

• Definitive results, available in November 2012

The thinking behind this model for dissemination of the census results made it possible to bring forward the availability of the census figures for a series of variables before completion of the data-processing procedure, thus being able to meet the users' principal needs. The information disseminated was already sufficiently coherent when it was made available, with the quantity of information continuing to increase until the final version (definitive results). Furthermore, the results for any given stage replaced those made available during the stage immediately prior.

19.2. Data revision - practice
Nothing to report.


20. Statistical processing Top
20.1. Source data
20.1.1. List of data sources
20.1.1.1. List of data sources - data on persons

Census questionnaires.

20.1.1.2. List of data sources - data on households

Census questionnaires.

20.1.1.3. List of data sources - data on family nuclei

Census questionnaires.

20.1.1.4. List of data sources - data on conventional dwellings

Census questionnaires.

20.1.1.5. List of data sources - data on living quarters

Census questionnaires.

20.1.2. Classification of data sources
20.1.2.1. Classification of data sources - data on persons
01.Conventional censuses
20.1.2.2. Classification of data sources - data on households
01.Conventional censuses
20.1.2.3. Classification of data sources - data on family nuclei
01.Conventional censuses
20.1.2.4. Classification of data sources - data on conventional dwellings
01.Conventional censuses
20.1.2.5. Classification of data sources - data on living quarters
01.Conventional censuses
20.2. Frequency of data collection

Data on population and housing censuses are collected every decade, in a reference year that falls during the beginning of every decade

20.3. Data collection

The collection model used an approach based on three levels of responsibility: National (INE), Regional (INE local offices and services of the Autonomous Regions) and Local (Municipal Chambers and Parish Councils). A hierarchical operating structure also exists at local level, with enumerators forming the base.

For the 2011 Census the methodology used for information collection involved distribution and collection by the enumerator, with self-completion of the questionnaires. For the first time in Portugal responses were provided over the Internet (e-Censuses) through a secure authentication system.

The fieldwork followed the schedule shown below:

    Distribution of the questionnaires: This phase lasted two weeks from 7 to 20 March 2011.

    Census day: 21 March 2011

    Collection period – This phase lasted five weeks from 21 March to 24 April. The collection was organised in three stages in accordance with the collection methods available (1st week – collection on the internet only; 2nd and 3rd weeks – Simultaneous collection (internet and paper questionnaires), 4th and 5th weeks – Collection of paper questionnaires)

Distribution of the questionnaires was supported by the Geographical Information Referencing Database  (BGRI2011), which enabled effective data collection in the field and subsequently made it possible to disseminate statistical information at detailed geographical levels, particularly at the level of small statistical areas.

The Fieldwork Monitoring System (SCTC) made it possible to systematise, standardise and monitor the whole process of distribution and collection of the questionnaires. Available online to the parties involved at all levels, it enabled users to obtain detailed, real-time information on the progress of the work at national, regional or local level.

20.4. Data validation

The final analysis of the consistency of the data involved implementation of various types of rules in order to verify the consistency of the data at different levels. Accordingly, various types of rules were defined:

    Rules applied to identify responses falling outside the range of values considered acceptable for the question;

    Rules to identify inconsistencies resulting from the incorrect completion of variables;

    Rules to define situations where the responses are inconsistent compared to other responses within the same statistical unit (intra-register rules) or by comparison to other statistical units (inter-register rules).

    Warning rules, aimed at evaluating the veracity of the responses; these are identified as situations which, while within the realm of possibility, are "strange" and must therefore be properly analysed.

Following the corrections stage the database was consulted again, using a wide range of queries to confirm its overall consistency.

20.5. Data compilation

Between the collection of the questionnaires and the dissemination of the results, the data from the 2011 Census were subject to a series of treatment processes that can be grouped into four stages.

1. Optical reading

Included the preparation of the questionnaires, involving verification and manual correction to the hierarchical and sequential ranking structure of the statistical units gathered on paper.

Digitalisation involved creation of images of the paper originals. The information was automatically recognised using ICR/OCR/OMR (Intelligent Character Recognition/Optical Character Recognition/Optical Mark Recognition) technologies.

2. Processing

During this stage the numerical characters that had not been recognised were processed and corrected and the validation rules defined for the fields containing such characters were checked.

The information gathered online was combined with the data from the paper questionnaires for further treatment.

During the validation of the hierarchy and numbering the hierarchy rules applicable to the questionnaires were validated.

During the intra-questionnaire validation and processing of alphabetical characters, the following were validated and corrected: the alphabetical characters in open questions; erroneous and duplicated markings; some validation rules. Problematic records were submitted to operators for manual correction.

During the sub-phase of validation and corrections of relationships any inconsistencies detected in the relationships between household members were addressed. During this sub-phase, the "Age" variable was also validated.

Expressions from open questions (countries, professions, etc.) were automatically coded using dictionaries and coding tables.  The system compared the expressions against those appearing in the dictionary; if the expression corresponded to the dictionary it was coded, if the expression was not recognised the record was returned to the operator for manual coding.

3. Automatic corrections

During the deterministic corrections sub-phase the consistency of the variables was assessed using a wide range of validation rules. Inconsistencies were addressed by means of deterministic corrections.

The "item non response imputation" sub-phase was intended to fill in gaps in the information by drawing on the rest of the information in the questionnaire or information from other questionnaires. Some variables were subject to deterministic imputation and others were imputed by Hot-deck.

4. Derived variables and specialisation

During this phase the derived variables resulting from the combination of information from one or more primary variables were calculated.

20.6. Adjustment


21. Comment Top


Related metadata Top


Annexes Top