Data stream for imminent study

[samreid]

As part of #96, we would like to make sure the data stream captures the data we want, and that it can communicate with metacog.

The client reported:

I did some pilot testing last Friday and over the weekend. Based on the observations, the most-needed log data includes:

• a clear signal indicating whether the user is in the “setup” or “test” state
• the model events in the test state – the weight and position of each individual items; the name of the items (“brick” or “mystery_box” and the angle of the balance beam is nice-to-have, but not necessary, as these information can be inferred

This data would yield information on how many trials the user ran and how each trial was set up.

[samreid]

Test is indicated in the data stream via NO_COLUMNS

          "index": 41,
          "time": 1580145627205,
          "type": "MODEL",
          "phetioID": "balancingAct.balanceLabScreen.model.columnStateProperty",
          "name": "changed",
          "componentType": "PropertyIO<EnumerationIO(DOUBLE_COLUMNS|SINGLE_COLUMN|NO_COLUMNS)>",
          "data": {
            "oldValue": "DOUBLE_COLUMNS",
            "newValue": "NO_COLUMNS"
          },

and setup is indicated via DOUBLE_COLUMNS

          "index": 58,
          "time": 1580145674501,
          "type": "MODEL",
          "phetioID": "balancingAct.balanceLabScreen.model.columnStateProperty",
          "name": "changed",
          "componentType": "PropertyIO<EnumerationIO(DOUBLE_COLUMNS|SINGLE_COLUMN|NO_COLUMNS)>",
          "data": {
            "oldValue": "NO_COLUMNS",
            "newValue": "DOUBLE_COLUMNS"
          },

[samreid]

Today @chrisklus and I made a recording with metacog, and tested that the data could be retrieved and played back visually. We used:

widget_id=balancing-act-1.2.0-dev.5-stanford

To Do:

• create an issue for this problem: https://github.com/phetsims/phet-io/blob/master/doc/metacog.md seem stale, refers to committing files to phet-io-website instead of adding entries to the file.
• decide how to publish, I'll create a separate issue for that, see How should the upcoming phet-io version be published? #105
• un-password-protect the wrapper for student use. Depends on prior checkbox

[samreid]

I'll consider this feasibility test complete. Next steps will be to publish a "production" version according to #105 and to un-password protect it.