How to tell how spells scale?

[Cainehill]

Is there a way to know how spell effects increase as the mage has more skill in the relevant path? It doesn't seem to be constant - for instance, Shards seems to give 2 extra stones per level of earth magic, while fire darts only gives one.

And damage is even harder to tell, unless all spells whose damage scales simply get 1 better per point of magic skill. Take Geyser - 6 AP damage, increasing with level. Does it definately only get to 9AP damage with W4?

[archaeolept]

I know the indefatiguable Zen has been working on a battlefield spells quick reference. but that may well be still a while in coming.