V2.0 (November 17, 2017)
The following is a sketch depicting a possible keyboard interaction for the Faraday's Law simulation (source: PhET). Understanding speed of magnet movement as it relates to flux is an important learning outcome, and this sketch aims to minimize the dexterity / motor function required to successfully gain the learning outcomes.
In the current simulation, the speed of which the magnet moves is directly correlated to the user's physical ability to manipulate the input device. This requires significant dexterity and motor function to accomplish.
In this design sketch, once the user as chosen a direction, the magnet will move in that direction on its own (continuously) like an object floating through space. The user can then choose to increase or decrease the magnet's movement speed (like a throttle), stop, or immediately reverse direction. By allowing the magnet to move on its own, this enables the user to focus on direction and speed without requiring significant motor control or dexterity.
Image 1 above: The initial screen for Faraday's law.
Image 2 above: Keyboard focus placed on the magnet.
Image 3 above: Enter is pressed and the user can begin to move the magnet in a direction they choose.
Image 4 above: User has pressed the left arrow key once, and the magnet begins creeping to the left by itself. A single arrow appears in the direction the magnet is moving that indicates it direction and speed.
Image 5 above: User has pressed the left arrow again, and the magnet increases its speed. Two arrows now appear in the direction the magnet is moving to indicate its direction and moderate speed.
Image 6 above: User has pressed the left arrow again, and the magnet is now moving at its maximum speed. Three arrows now appear in the direction the magnet is moving to indicate its direction and maximum speed.
Image 1 Above: Initial view
Image 2 Above: User has pressed tab and focus is moved to the magnet.
Image 3 Above: User has pressed Enter, and the magnet is now able to be moved using keyboard.
Image 4 Above: User is in a move state and is also pressing a modifier key, the magnet moves in larger steps. The arrows on the magnet change to visually indicate the change.
Image 5 Above: User is holding a different modifier key, the magnet moves in smaller steps. The arrows on the magnet change to visually indicate this change.
Image 6 Above: Describes a possible issue with keyboard interaction and speed of moving the magnet.
Current is related to the speed of magnet movement.
Faster the magnet moves, the greater the current.
Slower the magnet moves, the smaller the current.
In this scenario to the left, it will take a keyboard user 4 keystrokes to move to the other side of the coil (as indicated by the green dots).
If the user has sufficient motor acuity, they can move the magnet quickly by holding down the modifier and repeated tapping of keys.
If the user does not have sufficient motor acuity, it will be difficult"