Dear all, hope you can help me out with the following.
During analysis of the motion tracker data for a unique user, we found some peculiarities. Unfortunately, a description of the Motion Tracker data is not provided in the data definitions, nor in / in the [paper](https://www.nature.com/articles/s41597-019-0016-7). We were wondering:
- How come there are very many double entries per healthID, containing exactly the same values for all variables?
- What does the +##:## (where # is a number changing across participants) mean in the variable _dateAndTime_? I assume it?s indicating a time zone, is it the difference with UTC?
- How was the type of activity classified/assigned/calculated? Did you do this yourself from the raw data (can we find any explanation on the steps you took do to so somewhere), or is the data provided like this by Apple/iPhone already?
- The variables _confidenceName_, _confidenceRaw_ and _confidencePercent_ all seem to express the same value. However, we are unable to find any information about what these variables express. How should we interpret these?
Created by Annemiek Silven avsilven * The app's behavior was not always as intended. There may be double rows in the Motion Tracker and HealthKit tables
* At the end of a datetime, a +##:## relates to the timezone
* The Motion Tracker data comes from [CoreMotion motionactivitymanager](https://developer.apple.com/documentation/coremotion/cmmotionactivitymanager) to understand the implementation, see the [MyHeart Counts repository](https://github.com/researchkit/myheartcounts) and the AppCore library linked therein.
* See [this documentation](https://developer.apple.com/documentation/coremotion/cmmotionactivity/1615433-confidence) and [code history](https://github.com/ResearchKit/AppCore/commits/master/APCAppCore/APCAppCore/Library/APCMotionHistoryReporter.m).