Before revision:  In this paper, we try to solve this issue, and propose two effective approaches , namely 1) mutual information  based estimation and 2) reconstruction loss based estimation , to measure the hardness of learning the representation for a word and determine its computational depth.
After revision:  In this paper, we try to solve this issue, and propose two effective approaches , namely 1) mutual information (MI) based estimation and 2) reconstruction loss based estimation , to measure the hardness of learning the representation for a word and determine its computational depth.