Before revision:  Motivated by the recent finding that random negatives are often too trivial to train a reliable model , we propose a hierarchical curriculum learning (HCL) framework that consists of two complementary curricula: (1) corpus-level curriculum (CC);
After revision:  Motivated by the recent finding that models trained with random negative samples are not ideal in real-world scenarios , we propose a hierarchical curriculum learning (HCL) framework that consists of two complementary curricula: (1) corpus-level curriculum (CC);