Guide to the Census of Population, 2016
Chapter 8 – Processing
The step after collection, known as the processing phase, began May 2, 2016, with the process of editing and coding responses for approximately 15 million private and collective dwellings.
Receipt and registration
For the 2016 Census, electronic responses from online questionnaires were received from the Collection Management Portal (CMP) and registered in the Census Processing System (CPS) hourly before entering the edit and coding workflow. CPS also registered interviewer responses received through the Census Help Line (CHL), non-response follow-up (NRFU) and failed edit follow-up (FEFU) on a regular basis during collection and/or follow-up.
Paper questionnaires that were returned by mail were registered in Canada Post sorting plants by scanning the bar code on the front of the questionnaire before delivery to the Data Operations Centre (DOC). To confirm receipt by Statistics Canada, the questionnaires were removed from the envelopes and scanned again at the DOC. Whenever Canada Post was unable to read the barcodes (for instance, when forms were inserted into envelopes backwards), the questionnaires were removed from the envelopes and the barcode scanned when the envelope was delivered to Statistics Canada.
Registrations of all questionnaires from Canada Post were transmitted to the CMP daily. Enumerators were notified (via the CMP) of which questionnaires had been received so that they could stop contact for these respondents during NRFU procedures.
Paper questionnaires that were completed by enumerators during NRFU were shipped by their supervisors (crew leaders) directly to the DOC where they were registered. All such questionnaires were then data captured similar to other paper responses.
Imaging and data capture
Once paper questionnaires were registered, the next step was document preparation and scanning for data capture of responses.
- Document preparation – Mailed-back questionnaires were removed from envelopes. In order to ensure that questionnaires were ready to be scanned, operators removed foreign objects such as clips and staples from the documents. Forms were also cut into single sheets using guillotines (large paper cutters).
- Scanning – Scanning, using high-speed scanners, created digital images from the paper questionnaires.
- Automated image quality assurance – An automated system verified the quality of the scanning for capture purposes. Images failing this process were flagged for rescanning.
- Automated data capture – Optical mark recognition (OMR) and intelligent character recognition (ICR) were used to extract respondent data. When the system could not recognize the handwriting (known as the write-ins), keying was done by an operator from the scanner images. Paper forms that could not be scanned (e.g., too damaged) or were filled out with a pen or pencil that could not be read by the automated capture systems, were sent for transcription (i.e., the data were transcribed to a new form).
- Check-out – This quality assurance process ensured that the questionnaire images and captured data were of sufficient quality and that the paper questionnaires were no longer required.
As the paper questionnaires were captured and the online questionnaires received, an interactive process of manual and automated edits was performed to ensure that problems and inconsistencies were identified and resolved.
- Blank and minimum content – This automated edit identified questionnaires with no information or insufficient information to continue processing. These cases were returned to the field for non-response follow-up (NRFU) by census enumerators.
- Multiple responses – A household may have multiple forms (e.g., large households require more than one paper form to complete the census). This automated edit identified households with one or more missing questionnaires. These cases were held in a queue until all questionnaires were received.
- Coverage edits – These edits were conducted for both private and collective dwellings and ensured that the reported number of members of a household was consistent with the responses provided, including the number of names listed. Errors were resolved by an automated process or through interactive verification by DOC staff by manually examining the captured data and scanned images (where available) to help determine the appropriate solution.
- Failed edit follow-up (FEFU) – Short-form questions that needed further coverage or content clarification were transmitted to the Statistics Canada regional offices for FEFU collection and transmitted back to the DOC for the CPS for subsequent processing.
Written responses were converted to numerical codes before they could be tabulated for release purposes. For the 2016 Census, all written responses on the questionnaires underwent automated and interactive coding to assign each one a numerical code using reference files, code sets and standard classifications. Reference files were built using actual responses from past censuses for the automated match process. Subject-matter experts are responsible for developing, testing and maintaining the reference files that are used for automated and manual coding. Subject-matter coded all the write-ins that were referred by the first- and/or second-level coders and certified the codes prior to delivery to edit and imputation.
Edit and imputation
The data collected in any survey or census contains omissions or inconsistencies. These errors can be the result of respondents missing a question, or they can be due to errors generated during processing.
After the initial editing and coding operations were completed, the data were processed through the final edit and imputation activity. The final editing process detected errors and the imputation process corrected them.
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