The National Schools Statistics Collection (NSSC) is a joint undertaking of the various State and Territory departments of education, the Australian Government Department of Education, Employment and Workplace Relations (DEEWR), the Australian Bureau of Statistics (ABS), and the Ministerial Council for Education, Early Childhood Development and Youth Affairs (MCEECDYA).

NSSC (non-finance) data are collated by the ABS and are sourced from administrative school enrolment databases from the various State and Territory departments of education for government data and the Australian Government Department of Education, Employment and Workplace Relations (DEEWR) for non-government data.

For information on the institutional environment of the ABS, including the legislative obligations of the ABS, which cover this collection, please see ABS Institutional Environment.

Schools, Australia (Cat. no. 4221.0) includes explanatory notes and glossary available on the ABS website.

Socioeconomic status is not yet available in the NSSC.

School student data are available by State/Territory and Indigenous status but are not currently available by socioeconomic status.

Information on Indigenous status is obtained from school enrolment forms which are generally completed by the primary carer of the child. The NSSC includes people who did not state their Indigenous status in the category 'non-Indigenous'.

This indicator is calculated by dividing the number of students in year 10 or year 12 in the reference year by the number enrolled at the commencement of secondary school some years previously (depending on jurisdiction). Hence the measure is an Apparent Retention Rate (ARR).

It is not a measure of the proportion of students who actually completed year 10 or year 12.

Relatively small changes in student numbers can create apparently large movements in retention rates, particularly in small jurisdictions. In addition, the rates in the smaller jurisdictions may be noticeably affected by changes in such factors as the proportion of ungraded and/or mature aged students from year to year.

All data are collected to standard classifications as stated in the NSSC Notes, Instructions and Tabulations manual. Data covers all students enrolled in school.

Each school provides information on their enrolments to the relevant State education department which then forwards aggregate data to the ABS.

The collection of data on students in non-government schools is coordinated through the Australian Government Department for Education, Employment and Workplace Relations.

The NSSC is based on information on each student enrolled at the time of the school census.

Care should be taken in the interpretation of ARRs as the method of calculation does not take into account a range of factors such as repeating students, migration, inter-sector transfers and enrolment policies. For further details on the accuracy of the NSSC methodology and ARRs, see the Explanatory Notes of Schools (Cat. no. 4221.0).

The ARR is based on those who are undertaking study at the year 10 or year 12 level as at August in the reference year and they may not go on to complete year 10 or year 12.

The NSSC data items used to construct the ARRs are consistent and comparable over time, and support assessment of annual change.

The ARR measures change over a period of time. The numerator and denominator are sourced from different annual cycles of the NSSC, to follow the same age-cohort. Given the long analysis period, student transitions, such as migration or re-entry to the school system, have an effect on the accuracy of this calculation. In addition, the denominator is sourced from two different NSSC years due to different starting years for secondary school. For example, for the ARR from year 7/8 to year 10 in 2009, the denominator for NSW, Vic, Tas and ACT is sourced from NSSC 2006 (year 7) and for Qld, WA, SA and NT is sourced from 2007 (year 8).

There is some variability in the reporting of Indigenous status, particularly in relation to not stated responses. This may result in some under reporting of Indigenous status, see Appendix 2: Collection of Indigenous Status of Students (Cat. no. 4221.0) 2009. Increases in the number of Indigenous students due to improvements in the reporting of Indigenous status may lead to increases in ARRs for Indigenous students independently of changes in actual retention.

Before sending data to the ABS, each State education department cleans the data and removes duplicate records so that students are only counted once. Due to the different enrolment systems, the ability to remove duplicates varies among jurisdictions and this may result in over-reporting of school students in some states. Decreases in the number of students due to improvements in the identification and removal of duplicate enrolments may lead to decreases in ARRs independently of changes in actual retention.