To my understanding, the preliminary is a choice of the school, and unlike the year before, the only things being tested in the HSC are topics learned in year 12, so the preliminary work is both useless and a waste of time, some of the OHS work we did might cross over a bit, but it doesn't matter ALL that much, the reason it ain't taught well is there is a big chance that the teachers haven't really taught these areas before, dw about it