Table 2.

Changes made to the microinteraction ecological momentary assessment (μEMA) protocol or technology before the main study in response to the pilot participants’ feedback.

	Pilot study	Main study
Physical activity and sedentary behavior questions	Asked at random	Asked as sensor-triggered questions based on wrist-accelerometer activity
Location-based questions	Asked at random	Removed from μEMA and included as part of mobile phone EMA to obtain semantic location labels
μEMA question selection	At random	Using filter-based sampling algorithm
Person-level characteristics and validation questions	Not included in pilot study	Included in main study to assess validity and add variety to questions on μEMA days
Thank-you messages after answering a μEMA question	Messages selected at random from a bank of 10 messages	Messages selected sequentially from a bank of >250 messages
μEMA prompt wait time	15 seconds	Increased to 20 seconds
μEMA prompt vibration	11 seconds of progressively intense vibration pattern	6 seconds (2-second vibration with 1-second pause)