Been reading a lot into UI design lately and Fitt's Law keeps popping up.
Now from what I gather its basically the larger an item is, and the closer it is to your cursor, the easier it is to click on.
So what about touch screen devices where the input comes from multiple touches or just single touches.
What are the fundamentals to take into account considering this?
Should it be something like, the hands of the user are on the sides of the device so the buttons should be close to the left and right hand sides of the device?
Thanks
Yes, for a touch screen Fitts' law has to be applied in three dimensions, so it's different from the classical mouse movement considerations.
As you say, the origin of the movement is often the default position of the finger. This varies a lot depending on the device where the screen is mounted. On a hand held device you might use the index finger of one hand, or the thumbs of both hands, depending on the design.
Also, on a touch screen you have to move the fingers away from the screen to see it, which makes the distance between controls less important as you move back to the default position between clicks.
What to consider besides Fitts' law is the intuitiveness of the interface. If a button appears where it's not expected, it doesn't matter how close it is, it will still take time to find it.