What’s the deal with keeping the menus short?
Firstly, unlike a main menu, which is practically guaranteed to come down from near the top of the screen, a shortcut menu can be opened from anywhere. The longer the menu is, the more likely it is to appear in a direction other than in its expected place to the southeast of the cursor. When that happens, the user’s muscle memory is broken and she is slower at finding the item she wants. This makes the menu less useful overall, even when it does appear to the southeast — because the user had to pause to make sure it would. And secondly, shortcut menus are less visible and therefore less familiar than main menus. So they need to be shorter to be memorable. A good length for a shortcut menu is about six items; the longest ones in this spec are thirteen items, which is really far too long, but there isn’t any obvious way to make them shorter without dropping features.
