CALCULATING PRELIMINARY ERP
8.7 The Census provides detailed information on the age-sex structure and location of the population, but it misses some people who should have been counted in the Census. In addition, while Census records with unknown Indigenous status remain not stated on the Census file, for the purposes of population estimation they are allocated to either Indigenous or non-Indigenous according to the distribution of stated responses within each age group, sex, Census form-type and SLA.
8.8 Preliminary PES estimates of net undercount for Indigenous persons in the 2006 Census were used at the national level and for five jurisdictional groups. These were;
- New South Wales/Australian Capital Territory
- Victoria/South Australia/Tasmania
- Western Australia
- Northern Territory.
8.9 Some level of geographic grouping was considered necessary because of the high sampling error for some states/territories.
8.10 The geographic level to which the preliminary 2006 PES results were disaggregated for ERP purposes was determined after consideration of the sampling error and possible bias resulting from the groupings. The relative standard error (RSE) of the estimates of the Indigenous population in the five jurisdictional groups ranged from 3.5% for the Northern Territory to 7.3% for Western Australia. The RSE for Australia (excluding Other Territories) was 2.6%.