It is coming up to exam time. It seems to me, that a large part of the stress of exam preparation is working out what to study first, and what to study most. If you really want to give yourself an ulcer adopt the view that you should know every topic equally and perfectly well. A more realistic outlook is that jumping through academic hoops is messy business - you have limited time, and limited resources. Personal productivity is an ebb and flow of priorities and energy levels.

Over the past couple of years, i've been developing a theory of exam preparation efficiency, which I will now outline for your consideration and evaluation:

STAGE 1 - The most advantageous study activity you can engage in at any moment is learning, studying, or practicing something you don't know. The less you know it, the more overall value you get out of each minute spent on it.

An example: Ian Thorpe is competing in a triathlon. He has an hour to spend training. As a champion swimmer an hour in the pool might improve his overall race time by a fraction of a second. Ian however, has never before ridden a bike. An hour spent learning to ride, may save him hours during the race. At least now he wont fall of his bike as half as much.

This holds true where the topics, areas, or skills contribute equally to the aggregate result. Furthermore, itonly holds true while your energy level and resources are equally suited to learning or practicing the available options (for example: while stats may be my weakest subject, it may not be my most efficient option until I have a calculator available)

STAGE 2 - The second most valuable study activity you can engage in at any moment, is identifying things you don't know. That is to say, second priority is hunting for Donald Rumsfeld's 'unknown unknowns'.

Some things are more unknown than others, and so, it is efficient to put them in order of least familiarity. Time spent in this hunting and ordering phase, is only efficient to the point that the extra value you will obtain from studying the idenitified areas in the right order, exceeds the time you are spending putting them in order.

It is only efficient to move from stage 1 to stage 2 when your top stage 1 priority is already more familiar than the things you'd be likely to find in stage 2, or when your energy level and resources are more suited to stage 2 than any stage 1 studying.

STAGE 3 - The third most valuable way to spend study time is over-learning things you already know well. A change from stage 1 to stage 3 is only warranted when you need a moral boost from reminding yourself that you have mastered some areas. A change from stage 2 to stage 3 is only warranted when stage 2 processing finds few remaining 'unknown unknowns'.

(STAGE 4 (the unofficial stage) - when all else fails, post something on your blog)

But if you can neither understand or remember any of that 3-stage mumbo jumbo, here is the take home message: be content that you're doing things in the right order. You're maximising your knowledge, not perfecting it. If you have to sleep, or eat, or give someone first aid, that's fine too. Because you're still doing everything in the order of contextual importance.