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 random negatives are often too trivial to train a reliable model , we propose a hierarchical curriculum learning framework that trains the matching model in an "easy-to-difficult" scheme. Our learning framework consists of two complementary curricula: (1) corpus-level curriculum (CC);