The primary reason is data availability. The data sources for access and continuation are different, and so there are some characteristics that are available on the data used for the continuation measures that aren’t available for the access measure.
This is also why ethnicity is reported differently for the access measure to the continuation measures – because it is collected differently on the data source used for access.
Although the two continuation measures use the same data sources, differences in the student characteristics used in the measures are still due to data availability.
The number of part-time students is much lower than the number of full-time students and so where there are challenges with data availability, these are amplified in the part-time population.
These challenges exist with the four characteristics introduced into the FT continuation measures in the last update in November 2020 (care experience, FSM eligibility, NS-SEC and parental education) and so none of these are used for PT continuation (see the update report for details).
Additionally, TUNDRA is not included in PT continuation because this measure is most applicable to those who were under 21 when they started their course, which is not the case for the majority of part-time students.