Background and Analysis
If you don't know what a heuristic is check here. The seminal list of UI heuristics can be found here
I have just reached the 10 hour mark of Mass Effect 2; some good 4 hours of that has been spent in the game's scanning minigame. After 4 hours I can only call the scanning system tedious. I have also been playing it on the PC. I found that after a few hours my right hand (mouse hand) gets tired, tense, and I get annoyed.
For those of you who haven't played it let me explain. As can be seen in this video, the player controls a scanning object that they move with the mouse. The scanner only scans when the player holds down the right mouse button and then fires a probe to gather resources with the left mouse button. A typical planet can take me 10-30 minutes each depending on how thorough I am being. Given that there are more than 40 planets in the game, that's a long time scanning.
When I started thinking about why my hand hurt so much I was reminded of a time when I played Okami on the Wii with a friend. While I could successfully perform the brush strokes after a few tries they never could. They repeatedly had to move too slow in order to make the precise brush strokes required. They mentioned that holding down the trigger on the wimote while moving it was tricky.
Between these two examples it got me thinking.
The largest problem seems to be that both the act of scanning and the act of using the celestial brush requires one to hold down a button (right button for mouse, the trigger in the case of the Wii). What happens physiologically is that in order to press a button tendons in your hand are pulled causing your hand and wrist to get tense; moving your hand around uses the same tendons or ones next to them. The result is that by holding down the button, you have reduced your ability to finely control the movements of your hand. An additional point in the case of the PC is that you have to deal with picking up the mouse in order to continue moving the scanner in one direction.
It would seem that bad control schemes diminish a player's ability to finely control their character resulting in frustration and annoyance.
So the heuristic that comes out from my analysis is this:
Do not have toggles on the same hand/device as movement
I don't have a 360 to test but the only way this could get through testing (provided Bioware did testing) is if the scanning trigger is not on the same side as the joystick you use to move the scanner.
What does everyone think? useful, not useful?