7. Data Issues
Tables of Census data are subject to random perturbation to protect the confidentiality of individuals. This is in accordance with the Census and Statistics Act 1905 which stipulates that no results will be released in a way which would enable particular individuals or households to be identified.
The random perturbation can be a source of frustration to users, particularly those with a lesser degree of familiarity with Census data, as it can result in inconsistency in the data. Given the greater range of products designed to suit users of varying familiarity with Census data, every effort will be made to minimise the need for randomisation in tables reporting basic statistics at an elementary level. However, as the degree of sophistication of tables increases, the need for random perturbation remains and it will continue to be used in the release of data for the 2011 Census.
The Census Products and Services section examines the final data from the Census and provides some data quality assessments for users. These are released in formats such as Census Papers on the ABS website, and are also used within the program for the development of the next Census.
The team looks into the data on a topic by topic basis, but not every data item collected in the Census is covered by a Census Paper. The papers focus on new topics (e.g. Grandparent families), and on topics that are of ongoing interest to Census data users (e.g. Housing, Income, Industry, Occupation), while others are developed if the need is identified. Non-response Fact Sheets are also prepared and released by the Census Products and Services section, listing non-response rates for all Census data items by state, territory, and Australia.
ABS classifications have been developed to maintain consistent statistical standards, which reflect real world scenarios, and provide comparability with international standards.
For information about major classification changes affecting the 2011 Census data, refer to Chapter 6: Changes between the 2006 and 2011 Censuses.