Attrition Rate

Attrition rate is a measure of the proportion of students leaving the higher education system after their first year.

The department publishes two types of attrition rates, Normal and Adjusted:

  1. Normal Attrition rate:

    The Normal Attrition rate for year(x) is the proportion of students who commenced a course in year(x) who neither complete in year(x) nor return in year(x + 1).

    The normal attrition rate calculation is based on a match process using the students' StudentID. This gives a "crude" attrition rate, which identifies students that neither complete a course nor are retained the following year at the same institution. Students who remained at the same institution, but changed course are not counted in the attrition group. Students who changed institution are counted as attrited.

  2. New Normal Attrition rate:

    The New Normal Attrition rate for year(x) is the proportion of students who commenced a course in year(x) who neither complete in year(x) or year(x + 1) nor return in year(x + 1).

    The normal attrition rate calculation is based on a match process using the students' StudentID. This gives a "crude" attrition rate, which identifies students that neither complete a course nor are retained the following year at the same institution. Students who remained at the same institution, but changed course are not counted in the attrition group. Students who changed institution are counted as attrited.

  3. Adjusted Attrition rate:

    The Adjusted Attrition rate for year(x) is the proportion of students who commenced a course in year(x) who neither complete in year(x) nor return in year(x + 1).

    The adjusted attrition rate calculation is similar to the normal attrition rate calculation however it is based on a match process using both the StudentID and the Commonwealth Higher Education Student Support Number (CHESSN) (See Note 1 below). This gives a more accurate attrition rate calculation, as it identifies students at either the same or a different higher education institution. In other words, if a student moves from one institution to another in the following year, he or she would be counted as retained in the adjusted attrition rate calculation, but attrited in the normal attrition rate calculation. For the adjusted attrition rate, it is only those students who left the higher education system entirely (that is, they were no longer at any institution) that are counted as attrited.

  4. New Adjusted Attrition rate:

    The New Adjusted Attrition rate for year(x) is the proportion of students who commenced a course in year(x) who neither complete in year(x) or year(x + 1) nor return in year(x + 1).

    The new adjusted attrition rate calculation is similar to the normal attrition rate calculation however it is based on a match process using both the StudentID and the Commonwealth Higher Education Student Support Number (CHESSN) (See Note 1 below). This gives a more accurate attrition rate calculation, as it identifies students at either the same or a different higher education institution. In other words, if a student moves from one institution to another in the following year, he or she would be counted as retained in the adjusted attrition rate calculation, but attrited in the normal attrition rate calculation. For the adjusted attrition rate, it is only those students who left the higher education system entirely (that is, they were no longer at any institution) that are counted as attrited.

Technical notes

For each commencing student, student status is reviewed to allocate a student to one of the following outcomes (1) completed (2) retained or (3) attrited. Outcome (1) is determined by searching to see if a student completed a course. Outcomes (2) and (3) are determined by searching for the student in year x + 1 (if the student did not have a completion). Calculations are then based on these three outcomes. For attrition rate, the calculation is:

  • Attrition rate = 100 x (number of attrited students/commencing students)

Adjusted attrition rate - The CHESSN is only required for Commonwealth Assisted students, which means the adjusted attrition rate calculation using CHESSN will not be available for some students (namely non‑Fee‑HELP fee‑paying students), although these students can still be matched using their Student ID if they studied the following year at the same institution. Adjusted attrition rates cannot be calculated for overseas students who do not have a CHESSN.

Note 1 The CHESSN was first implemented in the Higher Education Student Data Collection in 2005 under new policy initiatives introduced through the Opens in a new window: Higher Education Support Act 2003 (HESA). See CHESSN definition.


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This glossary item applies to the collection types:
  • Higher Education Student Collection