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Based on feedback from user testing (see: PhET Faraday's Law - Gatech Interviews Notes), a number of issues were observed. This "Grab and Release" interaction sketch aims to address a number of these issues.

Observed IssueExample / RemarkGrab and Release Solution

Too many alerts

Every cursor key press and release would fire location text alerts

Location text alert now fired only on release of magnet.

Sonification will now be mostly uninterrupted.

Hard to concentrate on sounds and screen readerUsers often focus on the text alerts and miss the relationship between the magnet movement and the induced charge.

Sonification will now be mostly uninterrupted.

Most text alerts have been removed from movement interaction loop, with the exception of a coil bump and play area edge bump alerts.

Text alerts can be out of sync with the sonificationOften when a sound event happens, like a coil bump or induced charge, text alerts report the magnets location which can create confusion or incorrect associations.Sonification will now be mostly uninterrupted.
Long alerts create cognitive loadWhen 2 coils are present, a text alert can be very long.

Alerts in general are now shorter and less complicated:

  • Removed play area location alerts.
  • Reduced the complexity of proximity and regions.
Coil bump sound can sometimes be ambiguousSome users incorrectly associated the bump coil sound with a goal accomplishment (i.e. paraphrasing "I got the magnet into the coil, and that sound means I made it.").A single text alert now fires when a coil bump occurs.
Slide key instructions are often missedMost users did not use the slide keys.Introduce slide key instructions on later magnet grabs (as to not compete with other instructions, and reduce cognitive load).
Not clear to some users how to begin moving the magnetOne user kept searching the Controls Area.Button to grab the magnet is now located in the Controls Area list with other controls.

Issues not yet addressed:

Observed IssueExample / RemarkNotes
Unclear what sliding doesWhen sliding occurs, the sim can be rather silent.
  • Is this a concern? Users may not have used it sufficiently to determine its usefulness.
  • Are there magnet movement sounds when sliding occurs? (i.e. movement ticks).
Unclear what voltmeter doesA number of users did know what the voltmeter was for.
  • Is this a concern? Most users will use FL in context of a learning unit.
  • The voltmeter could be defined in the description instead (i.e. "Voltmeter - measures the positive / negative charge flowing through the circuit.")
  • The voltmeter is initially available - AP suggested it should be hidden by default

PDOM Example

Faraday's Law (h2, Scene Summary)