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2. North - West European
3. Southern and Eastern European
4. North African and Middle Eastern
5. South-East Asian
6. North-East Asian
7. Southern and Central Asian
8. People of the Americas
9. Sub-Saharan African
0000. Inadequately described
0901. Eurasian, so described
0902. Asian, so described
0903. African, so described
0904. European, so described
0905. Caucasian, so described
0906. Creole, so described
&&&& Not stated (applies to ANC1P only
@@@@ Not applicable (applies to ANC2P only)
VVVV Overseas visitor
Total number of categories:
one digit level 9
two digit level 36
four digit level 274
More Detailed Description
Quality Statement - Ancestry
There are many aspects which can affect the quality of Census data; the following information should be considered when viewing data on Ancestry.
The ancestry data collected in the Census is a measure of self-identification of ethnic or cultural group affiliation and therefore provides a broad measure of cultural diversity.
Most of the data (84.4% for Ancestry 1 (ANC1P) and 94.0% for Ancestry 2 (ANC2P)) was captured automatically from check box responses where the risk of processing error is minimal. The remainder were written responses which were coded by an automatic reading and coding process (13.2% of ANC1P and 5.4% of ANC2P), or coded clerically (2.4% ANC1P and 0.6% of ANC2P). A very small number were difficult to clerically code (0.2% for ANC1P and 0.1% for ANC2P) and more relaxed rules were used by coders. All coding is subject to sample checks to ensure an acceptable level of quality.
The non-response rate for ANC1P in 2006 was 8.1% compared with 6.9% for ANCP in 2001 (note that ANC1P for 2006 and ANCP for 2001 are the data items that contain not stated for Ancestry). Part of this non-response is attributable to the 4.1% of persons in dwellings which were occupied on Census Night but did not return a completed form. Persons are imputed into these dwellings together with some demographic characteristics. However the values for ANC1P remain not stated. In 2001, 2.1% of persons were imputed into dwellings for which no form was received.
Inadequately described responses (written responses unable to be coded) were 0.1%, down from 0.4% in 2001.
Scottish ancestry (in terms of responses for both ANC1P and ANC2P) has risen from 2.9% of persons (2.4% of all responses) in 2001 to 7.6% of persons (5.9% of all responses) in 2006. This may be partly due to its inclusion in the list of check box responses. The list of check box response options is updated for each Census to reflect the ancestries most commonly reported in the preceding Census. Revision of the list of check box response options between 2001 and 2006 may have also resulted in a small decrease in reportage of Greek ancestry, which did not appear in the list for the 2006 Census. These issues are discussed in more detail in the following Ancestry Census Fact Sheet.
There were some cases where dual ancestries were provided (for example, Fijian Indian) and attempts were made to code as one ancestry, but if this was unsuccessful they were coded separately as ANC1P and ANC2P. This represents a change from 2001 where they were more likely to have been coded as separate ancestries.
In a small proportion of cases (testing has indicated that this is around 3%), respondents provided an incorrect number of responses (for Ancestry, respondents were asked to mark up to two responses). In these cases responses are accepted in the order they appear on the form and the extra responses are rejected.
The ABS aims to produce high quality data from the Census. To achieve this, extensive effort is put into Census form design, collection procedures, and processing procedures.
There are four principal sources of error in Census data: respondent error, processing error, partial response and undercount. Quality management of the Census program aims to reduce error as much as possible, and to provide a measure of the remaining error to data users, to allow them to use the data in an informed way.
When completing their Census form, some people do not answer all the questions which apply to them. In these instances, a 'not stated' code is allocated during processing, with the exception of non-response to age, sex, marital status and place of usual residence. These variables are needed for population estimates, so they are imputed using other information on the Census form, as well as information from the previous Census.
The processing of information from Census forms is now mostly automated, using scanning, Intelligent Character Recognition and other automatic processes. Quality assurance procedures are used during Census processing to ensure processing errors are kept at an acceptable level. Sample checking is undertaken during coding operations, and corrections are made where necessary.
The Census form may be completed by one household member on behalf of others. Incorrect answers can be introduced to the Census form if the respondent does not understand the question or does not know the correct information about other household members. Many of these errors remain in the final data.
More detailed information on data quality is available in the 2006 Census Dictionary (cat. no. 2901.0), in the section titled Managing Census Quality.