Position slider's verbose aria-valuetext: describe position instead of providing a kilometer mark

[terracoda]

With some indication from interviews...Providing both the kilometer mark and distance from other sphere on focus of a mass position slider may not be super helpful.

The values together seem to be a bit of information/number overload, and it is not clear to @terracoda if the kilometer mark value is of much importance to the the learning goals of the simulation. Initial thinking was that the kilometer mark could provide some orientation of where the sphere is positioned along the invisible track of the slider.

Questions:

• Is position along track at all useful? If so, perhaps a described position would be better?
• Would it be better to just focus on distance throughout the entire position interaction (from focus to change of focus)?
• It might be much more useful to include some wording that makes it clear that the distance provided is the "distance between centers of spheres" in the more verbose aria-valuetext provided on focus.

Note that a dynamic verbose value for aria-valuetext is dependent on phetsims/scenery#951

Note that examples do not include the brief focus alert describing the size of the force arrows.

Currently, verbose aria-valuetext provides:
With Distance checked kilometer mark and distance in kilometers:

• 2.8 kilometer mark, 4 kilometers from ‪mass 2‬, mass 1 position slider.

With Distance NOT checked kilometer mark and described relative distance:

• 2.8 kilometer mark, close to ‪mass 2‬, mass 1 position slider.

Initial idea for a change to the verbose aria-valuetext
Option 1: Remove positioning along track all together and add "center" somewhere
With Distance checked, distance in kilometers:

• 4 kilometers from ‪center of mass 2‬‬, mass 1 position slider
• 4 kilometers from ‪mass 2‬‬'s center, mass 1 position slider
• mass 1's center, 4 kilometers from mass 2's center‬‬, mass 1 position slider

With Distance NOT checked, described relative distance:

• Close to center of ‪mass 2‬‬, mass 1 position slider
• Close to ‪mass 2's center‬‬, mass 1 position slider
• mass 1's center, close to ‪mass 2's, mass 1 position slider

Option 2: If position is needed, describe position on track instead
With Distance checked, distance in kilometers:

• On left side of track, center 4 kilometers from ‪center of mass 2‬, mass 1 position slider.
• On left side of track, center 4 kilometers from ‪mass 2's, mass 1 position slider.
• On left side of track, mass 1's center, 4 kilometers from ‪mass 2's‬, mass 1 position slider.

With Distance NOT checked, described relative distance:

• On left side of track, close to center of ‪mass 2‬, mass 1 position slider.
• On left side of track, center close to mass 2‬'s , mass 1 position slider.
• On left side of track, mass 1's center, close to mass 2's‬, mass 1 position slider

If described position in Option 2 is needed, possible descriptions for track position could be:

• On left side of track
• On right side of track
• Halfway along track (May not be needed. Could just not describe this position all.)

We already have 3 position landmarks implemented:

• Left edge (0 kilometer mark)
• Right edge (9.6 kilometer mark)
• Last stop (when spheres can't get any closer together)

Edited: Change number of interviews.

[terracoda]

@emily-phet, do you see what I am trying to do with these descriptions?

1. Do you think we need to provide position at all?
2. If so, do you think any of the drafted example values might be better than using "kilometer mark"?
3. Do you have a preference any of the phrases that describe the centers between the spheres?

[terracoda]

Feedback from March 12th Design Meeting:

1. Do you think we need to provide position at all?

• Yes, we do not think we have enough data yet to drop position all together, so @terracoda will iterate on position by adding in at least 2 more orientating descriptions to indicate which side of the track a mass is currently on.

2. If so, do you think any of the drafted example values might be better than using "kilometer mark"?

• We'll try something like Option 2, but without any mention of centers of spheres/masses.

3. Do you have a preference any of the phrases that describe the centers between the spheres?

• We won't be adding "center" to the focus information. It is ok to leave that detail in the PDOM. We want students to understand the relationships between distance/force and mass/force. The fact that the force vectors start at the centers and distance is measured from the centers of the spheres is important, but secondary.

[terracoda]

@terracoda to update design document examples and walkthrough with new phrases for position and distance.

• examples updated
• walkthrough updated

Note that having different (more versbose) aria-valuetext on focus is dependent on phetsims/scenery#951.

[terracoda]

@zepumph, I removed "describe center explicitly" from title as we decided not to consider doing that.

[terracoda]

I have a couple options for the phrasing to discuss at Tuesday's GFLB design meeting, so marking as a meeting issue one last time before implementation.

[terracoda]

@zepumph, I've got all position/distance changes updated in the design document and will be assigning things over to you after Tuesday's design meeting when I clarify the wording on a couple of phrases.

[terracoda]

@zepumph, the changes for position/distance are summarized in section Summary of position/distance

The Table: Position Regions & Landmarks outlines the strings that replace all the kilometer-mark positions. These are the biggest changes.

The examples demonstrated in the tables for focus events and the big cognitive walkthrough have all been updated. Changes are noted in red. And I left the current implementations there, but crossed out.

Notes in the last column describe what is verified and working (green highlights) and where there are issues (red highlights) or red comments.

I hope this all makes sense. If not, we can discuss late Tuesday/early Wednesday, I am now on Daylight Savings time, too.

[terracoda]

Marking as high priority in case it is possible to get these changes in for interviews in the later half of next week.

[terracoda]

@zepumph, #107 (comment) is basically contains three tasks that all intermingled:

Task 1: Replace all strings that contain kilometer marks (position value) with one of the new described position regions or landmarks. All together there are about 6 described position values which are laid out the Table: Position Regions & Landmarks:

• Left side of track
• Right side of track
• Last stop right (mass 1 only)
• Last stop left (mass 2 only)
• Track end left (mass 1 only)
• Track end right (mass 2 only)

Task 2: Adjust aria-valuetext on focus for the mass position sliders

• Examples are in the Table: Focus events for Move mass 1 slider

Task 3: Use the Cognitive walk-through as a guide to update aria-valuetext and alerts provided during interaction with the Move mass sliders

• See Cognitive Walkthrough

I hope that makes things more clear. I can make 3 issues if yo would prefer. Apologies for the mega-issue.

[zepumph]

@terracoda hopefully a lot/most of this is accomplished. Like you predicted, I was able to simplify quite a bit of logic in PositionDescriber, because the "edge cases" are built into the main value text generating function. I don't think this is without quirks and bugs, but I walked through the walkthrough, only looking at the white rows (with distance checked), and things are looking pretty nice!

I'm excited to talk tonight.

[terracoda]

@zepumph, we have some issues with the grey rows.
I am going to verifu what's working and then it might make sense to stat a new issue to resolve the issues with the grey rows in the walk-through.

Task 1: Is working perfectly. I do not hear kilometer marks, and instead get descriptions of my place along the track. I get correct aria-valuetext on focus and then while interacting I get the new aria-valuetext (distance in kilometers) and force alert with every step. The progress indicators also work perfectly with Distance checked. I get progress & distance on first step and all subsequent changes in direction.

Task 2: The aria-valuetext of a position slider on focus with or without Distance checked is working perfectly. I hear the described position on the track and distance in kilometers with Distance checked. I hear the described position on the track and the described region name for distance when Distance is not checked.

Task 3 (with Distance checked): Yes, the white rows, which represent what should be heard when Distance is checked, work perfectly! I hear the progress indicators with distance in kilometers on first step and on directional changes. I hear distance in kilometers on subsequent steps in the same direction. I hear the position landmarks and distance in kilometers at min and max positions (track ends, and last stops).

Task 3 (with Distance not checked): The grey rows, however, where we are to get described regions for position rather than actual distance in kilometers are working a bit erratically. In fact, I think Voice Over is reading out the aria-valuetext erratically. As I do not get the region name on every step, and after the first step, I don't seem to get the progress indicators. Frequently after the third step, I only hear alerts - no aria-valuetext at all.

@zepumph, I am going to close this issue - as all 3 tasks were implemented - and start a new one to focus on the issues in Task 3 (Distance not checked). Since the aria-valuetext works fine in VoiceOver when Distance is checked, I have the feeling there is something in the implementation that is different when Distance is not checked which needs to be investigated more deeply.

[terracoda]

Oops did not mean to post - will edit previous comment.

[terracoda]

@zepumph, I significantly updated #107 (comment).

[terracoda]

And will start a new issue for Task 3 (with Distance not checked).