Guide to the Census of Population, 2021

Release date: November 17, 2021 Updated on: November 30, 2022

This reference document provides an overview of the Census of Population content determination, collection, processing, data quality assessment and data dissemination. It may be useful to both new and experienced users who wish to familiarize themselves with and find specific information about the 2021 Census.

Table of contents

Chapter 1 – Introduction

General information
Why does Statistics Canada conduct the Census of Population?
Why is the census in May?
Privacy and confidentiality
Consent to release personal information
Retention of census information
Official languages
Other languages and alternative formats

Chapter 2 – Census history

Impact of COVID-19 on the 2021 Census of Population

Chapter 3 – Communications

Key activities
Census website
Social media
Respondent relations
Media relations
Outreach, public relations and events
Strategy for Indigenous and northern communities

Chapter 4 – Content determination

How are the census questions determined?
Content consultations
Questionnaire content qualitative test
2019 Census Test
Content test
Field operations test
Changes to the questionnaire for the 2021 Census
New content
Other changes
Overview of how Gender-based Analysis Plus considerations were made for the content/questionnaire
Additional references

Chapter 5 – Census of Population questionnaires

Short-form questionnaire (forms 2A, 3A and 2C)
Long-form questionnaire (forms 2A-L and 2A-R)
Forms used to enumerate usual residents of collective dwellings

Chapter 6 – Online questionnaire

Online versus paper questionnaires
Mobile-friendly responsive design

Chapter 7 – Field operations

Census delivery methods
Census wave approach
Census Help Line
Occupancy verification and follow-up activities for the 2021 Census

Chapter 8 – Processing

Receipt and registration
Imaging and data capture
Response database
Edit and imputation

Chapter 9 – Data quality evaluation

Why evaluate the quality of census data
Main types of errors
Evaluating data coverage
Quality indicators
Total non-response rate
Comparison between the total non-response rate in 2021 and the global non-response rate of previous censuses
Quality indicators by question
Quality indicators based on variance
Measuring sampling errors
2021 Census of Population response rate
Comparability of estimates from the 2021 Census and the 2016 Census programs
Comparability of the variability of estimates from the 2021 and 2016 Census long-form questionnaires

Chapter 10 – Dissemination

How census data are used
Overview of 2021 Census of Population products and services
Connecting with Canadians
Availability of products and services
Protecting privacy

Chapter 11 – Census geography

National Geographic Database
Hierarchical model of geographic areas for collection
Hierarchical model of geographic areas for dissemination
The hierarchy of geographic areas: Understanding the hierarchy, how geographies are related and data analysis
Geographic areas for dissemination
Non-standard or user-defined geographic areas for dissemination

Chapter 12 – Sampling and weighting for the long form

Appendix 1.1 – Legislation

Requirement to respond
Constitutional law

Appendix 1.2 – Difference between census counts and population estimates

Appendix 1.3 – Information produced from the 2021 Census of Population

Who is included in the population of Canada?
Where are people counted?
Who is included in the disseminated data for each topic?

Appendix 1.4 – Impact of the COVID-19 pandemic

Content determination
Data quality

Appendix 1.5 – Incompletely enumerated reserves and settlements

Appendix 1.6 – Percentage change for population and dwelling counts at various levels of geography

Appendix 1.7 – Use of administrative data to impute non-responding households in areas with low response rates

Objectives for the imputation plan
Development of the imputation plan
Results of the administrative data imputation tests
Implementing the administrative data imputation plan
Administrative Data
Reference date
Scope of the imputation plan
Data quality

Appendix 1.8 – Variability of estimates from the 2021 Census long-form sample

Analysis of the 2016 and 2021 Census long-form coefficients of variation

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