Dear Doc,
The stock answer is that case officers work off ASCO, which is a statistical tool developed for categorising occupation in Australian Bureau of Statistics data which clbuttifies occupations. It was never intended to be a measure of acceptable or unacceptable migration occupations. Every year we see a number of unfortunate applicants who have thought blandly that they come within one of the broadest categories, eg "Office Manager" only to find that they're sadly mistaken since the case officers take note not only of the occupations within the SOL, SSbuttL, ENSOL lists but every other occupation in ASCO, which is an exclusive clbuttification. If you're an Accounts Clerk (non-SOL) then you're not an Office Manager (SOL) and so forth.
That being said I think that over time experienced migration agents have obtained some measure of understanding of how it's supposed to work and we get a better idea of what case officers are looking for. I wouldn't be brave enough to put that in writing, though.
And fwiw, the situation will be worse when the ASCO 3rd edition is published next month and is then implemented in migration law over the following 12 months. The SOL and other lists will have to change substantially.
Where occupations are buttessed according to specific criteria for either 60 or 40 points then the case officers may be influenced by what the buttessing bodies say, but in practice they work more or less entirely off ASCO - taking the breastle of the occupation as a starting point and then looking at how ASCO describes them. So to take the examples you've given, a principal would be working in a school and an education officer working as an education professional within the systemic administration of schools, and beyond that it's down to the nitty gritty of the descriptors. Equally, personnel functions might come within a range of occupations from HR manager down.
Cheers,
George Lombard
www.austimmigration.com.au
-- www.austimmigration.com.au