Modeling the coherence among sentences to compute their gold order is one of the fundamental tasks in Natural Language Processing (NLP) with many applications such as document modeling (Narayan et al., 2018a), extractive document summarization (Jadhav and Rajan, 2018;Nallapati et al., 2017), question answering Liu et al., 2017), conversational analysis (Zeng et al., 2018), automated text generation (Guo et al., 2018), and image captioning (Anderson et al., 2018).
positional Accuracy (pAcc in %): The positional accuracy is defined as the ratio of the matched sentence-level absolute positions between the predicted and correct orders as follows: where o s j denotes the absolute position of sentence s j in the correct sequence S j .