on entropy (ME) is a measure of the "information content" in the patterns of methylation reported by the sequencing reads, it could also be thought of as a measure of the randomness in the epialleles (an "epiallele" is the DNA modification at a given position).
This metric was originally proposed by <a href="https://academic.oup.com/nar/article/39/10/4099/1303103#82681132">Xie et al.</a> and has been shown to correlation with <a href="https://academic.oup.com/nar/article/51/5/2046/7033790">regulation</a>, <