Gamified interfaces have the potential to motivate children’s everyday physical activity. An activity model should allow for unobtrusive data input and offer interpretable output for gamified feedback. We define a physical activity user model that uses smartphone sensor data to learn the children’s activity level according to classes of MET scores. We conduct a user study using a pre-/post-test design with 61 children to measure the accuracy of the the predicted activity classes compared to accelerometer data. 19 of these children receive gamified feedback on their activity level using a mobile application.We analyze how the effect of the motivational interface compares to influence factors. This work combines user activity modelling with motivational interfaces and offers insights into the limits and chances of applications designed for children.     «

Gamified interfaces have the potential to motivate children’s everyday physical activity. An activity model should allow for unobtrusive data input and offer interpretable output for gamified feedback. We define a physical activity user model that uses smartphone sensor data to learn the children’s activity level according to classes of MET scores. We conduct a user study using a pre-/post-test design with 61 children to measure the accuracy of the the predicted activity classes compared...     »