A question that is often posed concerns the relationship between the number of units studied and the
UAI: ‘Do students gain a better UAI if they study more units?’ The data in Table A7 in the Appendix
show that students with high UAIs tend to have studied more than 10 units, but determining causality is
difficult. It is likely that the more academically able students complete more units, so it is not surprising
that they gain higher UAIs. On the other hand, if students only study 10 units of UAI courses and do
badly in one course, their UAIs will be depressed.
To address this question, HSC students were grouped according to their achievement in the SC
examination. What the data show is that the better students did, indeed, tend to study more units and within
each group there was a tendency for students who studied more units to obtain higher UAIs.
This does not, however, completely answer the question of causality. The relationship between number
of units studied and UAI within each group might result from personal attributes including interest,
motivation, effort and time management. One cannot assume that simply by studying more units,
one’s UAI will be increased!