What does "Calm" mean?


Could someone please describe how the value on the scale Calm --> Active is calculated in the Calm app? Does the app use an algorithm similar to the calculation of the experimental parameters, ‘concentration’ and ‘mellow’ described in the SDK documentation?

After lots of trials with the Calm app, it seems to me that it’s telling me more about whether I have had my eyes open or closed than whether my meditation was calm.

Thanks for any insights on this.