Spell Effect Sizes?

When you increase the area of an effect spell, does the effect grow bigger of smaller?

If not, then how are way you can change it to make it smaller/bigger?

When you increase the AOE, it increases how large the area is when the spell is used. i.e. The mortar teams has spash damage... same thing.

The effect itself has a fixed size. The only way to modify it is to either make the effect a projectile of a dummy unit which can then be scaled, or if the effect is a unit by itself.

However that is not always the case, some effects have some limited 'scaleability' for example blizard with a larger AOE covers more area graphically.