“…In the analysis of behavior entropy, we firstly focus on the record of a learner’s behavior throughout the day (i.e., {t 1 , t 2 , ···, t n }). Subsequently, we divide one day into 48 time bins such that each bin spans 30 min [ 14 , 18 , 19 ]; therefore, every bin is encoded from 1 to 48 (i.e., t i ′∈ {1, 2, ···, 48}, where i denotes the i th time bin). Then, the time series {t 1 , t 2 , ···, t n } can be mapped into a discrete time sequence {t 1 ′, t 2 ′, ···, t n ′}.…”