Workshop on Census Data Processing: Contemporary Technologies for census Data Capture and Data Editing Organised by United Nations Statistics Division (UNSD) in conjunction with the National Bureau of statistics (NBS) Dar es Salaam , Tanzania, 9 – 13 June 2008
Country ReportPresented by Mrs. N.Gujadhur Central Statistics OfficeMauritius June 2008
Islands of Mauritius and Rodrigues • Capital: Port Louis • Population : 1.26 mn • Population growth rate: 0.6% • Area: 2,040 km2 • Population density: 616 persons/km2 • Monetary unit: MRupees • Literacy rate : 85% • Languages: English & French
Outline • Census taking in Mauritius • Core topics covered in 2000 HPC • Editing and coding • Data Processing • Data Capture Outsourcing • Data Validation & Tabulation • Problems
Census taking in Mauritius • 1st complete Census in the Island of Mauritius was undertaken in 1735 • Since then, censuses have been taken in 1846, 1851 and every 10 years up to 1931. • After the 2nd World War, the ten-yearly programme was resumed and Housing and Population censuses were undertaken in: 1952, 1962, 1972, 1983, 1990 and 2000 • Next census => 2010
Census Organisation/Documentation The 2000 Housing & Population Census (HPC) was conducted in the Island of Mauritius, Rodrigues and Agalega. • Enumeration forms, Instructions & codebooks were the main source of documentation used during the HPC. • 1st round - Housing Census • Chief Enumerators enumerated all buildings, housing units, households, commercial establishments, hotels, institutions etc. • Enumeration Books, each containing 25 Housing forms.
Census Organisation/Documentation (Cont’d) • 2nd round - Population Census • Enumerators enumerated all persons present on census night as well as usual residents who were away on census night. • A Population questionnaire was used to collect information. • Details instructions were provided to Supervisors, Chief Enumerators and Enumerators. • A Census Guide and Instructions was also given to head of household for completing the Population questionnaire.
Principles and Recommendations for Population and Housing Censuses The Core Topics covered in the 2000 Housing Census were: • Type of living Quarters • Location of living quarters • Occupancy status • Type of Ownership • Numbers of rooms • Water supply system • Toilet • Sewage disposal • Bathing facilities
Principles and Recommendations for Population and Housing Censuses (Cont’d) Core Topics for Housing Census • Availability of kitchen • Fuel used for cooking • Type of lighting/Use of electricity • Solid waste disposal • Number of Occupants • Type of tenure • Type of building • Construction material of outer walls
Principles and Recommendations for Population and Housing Censuses (cont’d) • The recommended core topics covered in the 2000 Population census were: • Geographical and Internal Migration characteristics - Place of usual residence and place where present at time of census • International Migration characteristics - Citizenship • Household and Family characteristics - Relationship to head • Demographic and Social characteristics - Sex, age and Marital status
Principles and Recommendations for Population and Housing Censuses (Cont’d) • Fertility and Mortality characteristics - Children ever born • Educational characteristics - Literacy, School Attendance and School Attainment • Economic characteristics - Activity Status, Occupation, Industry and Status in Employment • Disability characteristics - Disability status
Editing and Coding – Housing Census • Housing Census questionnaires started during the 2nd week of March 2000 and was completed during the 1st week of May. • 30 editors and coders and 3 supervisors and about 310,000 Housing Census forms were edited and coded. • ½ day training for the editors and coders. Training was an on going process. Short briefing sessions were conducted as and when needed.
Editing and Coding – Housing census (cont’d) Editing and coding was done manually. • (i) Verified that geographical identifiers on the cover of booklets making the EA batch were the same. • (ii) Consistency checks of block numbers, building numbers within blocks as well as the housing units within buildings were then performed.
Editing and Coding – Housing census (cont’d) • (iii) Some examples of the consistency checks - if “ Roof” = concrete slab, then “ Walls” should also be stone, concrete, concrete blocks, and bricks. - if Bathing Facilities is marked, then “HU3 – Water Supply” should be Piped water inside housing unit. - Ensure that the no. of Male and Female in column “No. of persons” add up to Total. - if tenure =Owner or free, monthly rent should be zero
Editing and Coding – Population Census • Population Census questionnaires started August 2000 and was completed in May 2001. • 50 editors and coders were involved and about 300,000 Census forms were edited and coded. • ½ day training for the editors and coders. Training was an on going process. Short briefing sessions were conducted as and when needed.
Editing and Coding – Population Census (cont’d) • Editing & coding of the Population Census forms was more complex and time-consuming than that of the Housing Census forms • Verification of the EA batches consisted of checking that all census forms in a given batch, • appropriate geographical codes were inserted on unaddressed forms, • consistency checking and editing of the individual forms according to “2000 Population census - Editing & Coding Instructions”.
Editing and Coding – Population Census (cont’d) • Some example of the checks • Check that there is one and only one head in every household. • Check the number of family nuclei • Check for possible inconsistency between name, relationship and sex for every person. • Check that age is consistent with date of birth. • Check marital status with age. • Check if age at first marriage is > 10 years • Check number of children ever born with age and sex. • Check education and highest qualification with age. • Check the internal consistency of the information on economic activity.
Editing and Coding – Population Census • Coding of Housing & Population Census International Classifications adapted to the country • National Classification of Occupations (Based on ISCO 88) • National Standard Industrial Classification of Economic Activities (Based on ISIC Rev. 3, 1990) • Codes for Vocational/technical/tertiary qualification (Adapted from ISCED) • Locality codes and country codes
Data Processing • The processing of the HPC data were done along the same lines, although the various operations involved in the processing were somewhat more complex for the PC than for the HC. • Data capture; • Data validation and updating of data files; • Production of address labels from Housing Census files and printing of labels; • Tabulation.
Data Capture – Outsourcing • Data capture for the 2000 H&PC was outsourced to another government organisation - The Central Statistics Office (CSO) does not have its own full-fledged IT department and - personnel capable of undertaking data capture activities. • Data entry was done by operators of the Central Information Systems Division (CISD) of the Ministry of Information Technology and Telecommunications.
Data Capture – Outsourcing (cont’d) • The data entry staff was composed of 28 operators and 5 supervisors. • The Data Entry operators were given a short training before starting the work, and short session were conducted as and when needed. • Coded questionnaires were sent to the CISD in EA Batches for data capture. All Housing and Population Census questionnaires were verified; i.e. Double entry.
Data Capture – Housing Census • Software used was IMPS 4.1 (Integrated Microcomputer Processing System) of the International Programs Center of the US Bureau of the Census. • The data entry exercise of about 310,000 HC forms started in March 2000 and was completed in May 2000. • Names and addresses of head of households were used as a frame for the Population Census enumeration.
Data Capture – Population Census • Data capture for the Population Census started in September 2000 and was completed in July 2001. • Data for around 300,000 Population Census forms containing about 1,200,000 records were keyed in during that period. • The CISD had recourse to extensive after-office work to complete the data entry exercise within reasonable time limits.
Data validation • A validation programme was run to identify records with errors. • Listings of these records were produced; relevant census forms were retrieved and corrections were made accordingly. • Data files were updated. • Once validation of all data files was completed, the data files were concatenated to the country level.
Tabulation • Tabulation was done using the CENTS module of IMPS. • A preliminary set of publication tables was produced using the country data file. • A list of relevant edit specifications was drawn and incorporated in a CONCOR programme to remove the inconsistencies from the tabulated data. • Table reports for Housing Census were completed in October 2000 and for Population Census in October 2001. • All publications are posted on the office website at the following address: http://statsmauritius.gov.mu.
Problems encountered during the 2000 HPC • Problems of shortage of staff were met at various stages of the census operation, causing delays on the time schedule. ( Fieldstaff, editors and coders, data entry operators) • As regards data capture, this was done by the Central Information System Division of the Ministry of IT and very often the census work was not given priority over other work thus resulting in delays.