Towards Human-Centered Summarization: A Case Study on Financial News
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Towards Human-Centered Summarization: A Case Study on Financial News Tatiana Passali1 , Alexios Gidiotis1 , Efstathios Chatzikyriakidis2 , and Grigorios Tsoumakas1,2 1 School of Computer Science, Aristotle University of Thessaloniki {scpassali,gidiotis,greg}@csd.auth.gr 2 Medoid AI {stathis.chatzikyriakidis,greg}@medoid.ai Abstract and Lapata, 2019; Song et al., 2019; Zhang et al., 2020) achieve great results in the task of summa- Recent Deep Learning (DL) summarization rization, outperforming most of the previously used models greatly outperform traditional sum- methods. Typical DL models involve sequence to marization methodologies, generating high- quality summaries. Despite their success, sequence architectures with RNNs (Nallapati et al., there are still important open issues, such as 2016; See et al., 2017) often combined with atten- the limited engagement and trust of users in tion mechanisms (Luong et al., 2015; Bahdanau the whole process. In order to overcome et al., 2015), as well as Transformers (Vaswani these issues, we reconsider the task of sum- et al., 2017; Lewis et al., 2020; Raffel et al., 2020a). marization from a human-centered perspec- Despite the success of DL models, some signif- tive. We propose to integrate a user inter- icant challenges remain. The low interpretability face with an underlying DL model, instead of tackling summarization as an isolated task of these models (Brunner et al., 2020; Vig and Be- from the end user. We present a novel sys- linkov, 2019; Serrano and Smith, 2019; Vashishth tem, where the user can actively participate et al., 2019) is a major drawback that limits signifi- in the whole summarization process. We cantly the trust of users in the whole process. also enable the user to gather insights into In addition, existing pipelines do not adequately the causative factors that drive the model’s engage the human in the summarization process behavior, exploiting the self-attention mecha- (Trivedi et al., 2018; Shapira et al., 2017), providing nism. We focus on the financial domain, in order to demonstrate the efficiency of generic isolated and static predictions. The engagement of DL models for domain-specific applications. users and their feedback in the whole process can Our work takes a first step towards a model- be a key factor in creating high-quality models and interface co-design approach, where DL mod- improving the quality of existing models (Stiennon els evolve along user needs, paving the way et al., 2020; Ghandeharioun et al., 2019). towards human-computer text summarization To overcome the above limitations, we revisit interfaces. the task of neural summarization from a human- centered perspective and with a unifying view of 1 Introduction user interfaces and underlying summarization mod- The ever increasing amount of online text docu- els. More specifically, we present a system that ments, such as blog posts, newswire articles and allows the active involvement of the user, setting academic publications, during the last decades, has the basis for human-computer text summarization created the urgent need for appropriate natural lan- interfaces. Our system allows users to choose over guage understanding tools. Summarization, i.e., different decoding strategies and control the num- shortening an initial text document by keeping only ber of alternative summaries that are generated. the most important information, plays a key role in Users can give their feedback by combining parts addressing this information overload. of the different generated summaries as a target A lot of sophisticated summarization models summary for the corresponding input. These sum- have been proposed in the past, with a recent focus maries are recorded, and can then be used as ad- on Deep Learning (DL) architectures. DL models ditional training examples, which in turn will im- (See et al., 2017; Kryściński et al., 2018; Celiky- prove the performance of the model and customize ilmaz et al., 2018; Chen and Bansal, 2018; Liu it to the preferences of the users. 21 Proceedings of the First Workshop on Bridging Human–Computer Interaction and Natural Language Processing, pages 21–27 April 20, 2021. ©2021 Association for Computational Linguistics
In addition, our system provides useful insights multiple attention heads. The attention weights about the inner workings of the model, based on the of each head are concatenated with each other to self-attention mechanism of Transformers. Know- compute the final weights. ing which parts of the source document are most Extracting the weights of each encoder layer sep- important for the generation of the final summary, arately, gives us useful insights about the model’s can build up the trust between users and the ma- behavior. In particular, we observe that different chine. layers give us different types of insights regarding We present a case study of the proposed system the way that the model perceives natural language. on the challenging, domain-specific task of finan- The first layers tend to focus on named entities and cial articles summarization, to demonstrate the abil- phrases taking a whole picture of the text, while ity of the suggested approach to successfully em- the last layers attend additionally prepositions and ploy generic DL models for domain-specific appli- articles in order to learn the language structure. In cations that often have different requirements. In- order to provide an overview of the model, we aver- deed, domain-focused summarization models (Kan age all the self-attention layers along with all their et al., 2001; Reeve et al., 2007) are generally more attention heads, giving the user an overall picture challenging, as they require deeper knowledge of regarding the model’s learning process. the specific domain intricacies in order to generate Assuming that a word which is attended by many salient summaries with logical entailment. To this words is more salient for the final decision of the end, we compiled a novel financial-focused dataset, model, we highlight the words according to their which consists exclusively of financial articles from self-attention weights. Thus, high-weight words Bloomberg1 . are strongly highlighted, while lower-weight words The rest of this paper is structured as follows. are faintly highlighted. This allows users to get a The main features of the proposed human-centered glimpse of where the model focuses on to generate system are detailed in Section 2. The case study on the final summary. financial news summarization is presented in Sec- 2.2 Decoding Strategies tion 3. Finally, conclusions and interesting future research directions are discussed in Section 4. The selection of the right decoding strategy during inference can play a critical role in the whole pro- 2 HCI meets Summarization cess as it greatly affects the quality of a model’s predictions (Holtzman et al., 2020), with different In this section we will introduce the main fea- decoding strategies exhibiting different behaviors tures of our human-centered summarization system. (Ippolito et al., 2019). Some decoding strategies, We first present the approach used for interpreting such as greedy search, suffer from redundancy is- the summaries generated by the model. Then we sues (Shao et al., 2017), while others, such as beam present the different decoding strategies we employ search, might generate almost identical hypotheses during inference. Finally, we explain how users can among the different generated beams (Gimpel et al., interact with our system. 2013). Beam search is widely used in generative 2.1 Peeking into the Black Box models, but there are also attempts that utilize other decoding mechanisms, such as top-k sampling (Fan Our interface assumes the existence of a et al., 2018b). Transformer-based model with self-attention Our system allows for the active involvement of (Vaswani et al., 2017), which are the backbone users into the underlying summarization process, of most modern summarization approaches. To by offering them the opportunity to select among provide insights into the produced summaries, we the following decoding strategies: exploit the fact that the self-attention mechanism offers an implicit explanation about the factors that • Random sampling selects randomly a token drive the behavior of the model. In particular, it out of the word probability distribution. Often helps the model identify input-output text depen- combined with a temperature parameter to dencies by focusing on different parts of the input control the entropy of the distribution (Ficler in order to generate the final sequence representa- and Goldberg, 2017; Fan et al., 2018b; Caccia tion. This mechanism is typically combined with et al., 2020). 1 https://www.bloomberg.com • Top-k sampling limits the space of possible 22
next tokens to the top-k higher-ranked tokens Table 1: Dataset Statistics of the distribution (Fan et al., 2018b) . Initial Preprocessed • Top-p or nucleus sampling selects the next min. document length (words) 20 79 token from a subset of tokens with cumulative max. document length (words) 3758 2537 probability up from a predefined threshold p avg. document length (words) 676 669 (Holtzman et al., 2020). It can also be com- avg. summary length (words) 23 23 bined with top-k sampling. # single-sentence summaries 21 0 # total documents 2120 2096 • Greedy search selects the token with the highest probability at each time step. • Beam search selects not only the token with 3.1 Dataset the highest probability at each time step, but We compiled a novel collection of financial news also a number of tokens with the highest prob- articles along with human-written summaries using ability according to the beam width. The num- the Bloomberg Market and Financial News API by ber of the final generated beams is equal to the RapidAPI3 . The articles concern different financial beam width. Beam search with beam width and business categories, such as stocks, markets, set to 1 degenerates to greedy search. currency, rates, cryptocurrencies and industries. We removed outlier documents, i.e., relatively • Diverse beam search follows the beam small (up to 70 tokens) and very large (over 3,000 search algorithm, but also adds a diversity tokens) ones. As most of the summaries consist penalty to enhance the diversity between the of two sentences, we also removed single-sentence top most probable generated beams (Vijayaku- summaries to maintain a consistent target structure. mar et al., 2016). Table 1 presents some basic statistics about our 2.3 User Interaction dataset before and after this simple pre-processing The interaction of a user with our system consists pipeline. of the following steps. It starts with the user enter- 3.2 Models ing the source text into a text box. Then users have the option to view the visualization of the attention We use the recently proposed PEGASUS model weights, as well as choose a particular visualization (Zhang et al., 2020), which is based on the trans- color. Next users can select among the available former encoder-decoder architecture. It features 16 decoding strategies, which also gives them the op- layers for both the encoder and the decoder, each portunity to change the default hyperparameters of of them with 16 attention heads. PEGASUS is each decoding strategy. Finally, they can click on already pre-trained on two large corpora, C4 (Raf- a button to obtain the summaries. It is also possi- fel et al., 2020b) and HugeNews, and fine-tuned ble for users to mix and match sentences from the on 12 different downstream datasets. The model alternative produced summaries, as well as enter uses SentencePiece, a subword tokenizer (Kudo their own text, in order to create a personalized and Richardson, 2018), which divides rare tokens summary. This summary can then be saved, and into known subword units allowing for the efficient later be used for further fine-tuning of the model. handling of unknown words. We experimented with two models fine-tuned 3 Case Study: Financial Summarization on two different newswire datasets respectively, In this section, we detail our experiments with the namely Extreme Summarization (XSum) (Narayan case study of financial summarization. We first et al., 2018) and CNN/Daily Mail (Hermann et al., describe the data collection process and the pre- 2015). We used the open-sourced weights of these processing steps we followed. Then we discuss the models to initialize our summarizers, and then models that we constructed and their evaluation. further fine-tuned them on the collected financial Finally we discuss concrete examples of the user dataset. experience. The code and instructions for this case We observed that both model variants quickly study of our system is publicly available2 . adapted to the new dataset, and after only a few 2 3 https://bit.ly/human-centered-summarization-notebook https://rapidapi.com/marketplace 23
Figure 2: Visualization of the encoder self-attention weights. The underscore before a token indicates the start of the token according to the subword tokenizer. Layer 1 Layer 6 Figure 1: Examples of generated summaries before and after fine-tuning. training epochs they were capable of generating salient, non-redundant financially-focused sum- maries, which target explicit economic and busi- Layer 16 ness issues. Examples of the generated summaries before and after fine-tuning are shown in Figure 1. Fine-tuning on our dataset, leads to an improve- ment in performance by approximately 10 ROUGE- 1 (F1 score) points (Lin, 2004) for the XSum model, which is eventually used in our system. The evalu- ation results are shown in Table 2. Table 2: Evaluation Results. We measure the F1 scores Figure 3: Self-attention weights of layers 1, 6 and 16. for ROUGE-1, ROUGE-2, ROUGE-L and ROUGE-S. CNN/Daily Mail model XSum model Fine-tuning R-1 R-2 R-L R-S R-1 R-2 R-L R-S order to capture phrases and sentences, while the No 20.00 4.86 15.04 16.97 13.80 2.40 10.63 12.03 last layers pay close attention to prepositions and Yes 23.34 6.30 17.98 21.04 23.55 6.99 18.14 21.36 articles attempting to learn language structure. An example of the output differentiation be- 3.3 Samples from the User Experience tween different decoding strategies for the same input text is shown in Figure 4. The different sum- An example of the visualized self-attention weights maries that are generated by the model, demon- is shown in Figure 2. The model focuses on basic strate the value of selecting an appropriate decod- named entities of the source text, which are indeed ing strategy for the final generation. important for the final generation. We also observe that different layer depths provide different insights 4 Conclusions and Future Work regarding the model’s learning process as shown in Figure 3. For example, the first layers attempt We presented a novel system for human-centered to focus on every word of the input document in summarization that actively engages the user into 24
(Kikuchi et al., 2016; Liu et al., 2018; Takase and Okazaki, 2019; Fan et al., 2018a), style (Fan et al., 2018a) or generation based on a specific entity of the text (He et al., 2020; Fan et al., 2018a). The interface we designed can be also further extended, allowing the user to evaluate the gener- ated summaries, assessing different aspects of the text, such as salience, readability and coherence. Finally, more advanced approaches can be explored for leveraging the user submitted feedback in order to further improve the underlying model (Lertvit- tayakumjorn et al., 2020; Li et al., 2016). References Dzmitry Bahdanau, Kyung Hyun Cho, and Yoshua Bengio. 2015. Neural machine translation by jointly learning to align and translate. In Proceedings of the 2015 International Conference on Learning Rep- resentations. Gino Brunner, Yang Liu, Damian Pascual, Oliver Richter, Massimiliano Ciaramita, and Roger Watten- hofer. 2020. On identifiability in transformers. In 8th International Conference on Learning Represen- tations, ICLR 2020, Addis Ababa, Ethiopia, April 26-30, 2020. OpenReview.net. Massimo Caccia, Lucas Caccia, William Fedus, Hugo Larochelle, Joelle Pineau, and Laurent Charlin. 2020. Language gans falling short. In International Conference on Learning Representations. Asli Celikyilmaz, Antoine Bosselut, Xiaodong He, and Yejin Choi. 2018. Deep Communicating Agents for Figure 4: Output for different decoding strategies. Abstractive Summarization. In Proceedings of the 2018 Conference of the North American Chapter of the Association for Computational Linguistics: Hu- man Language Technologies, Volume 1 (Long Pa- the whole process of summarization, enabling per- pers), pages 1662–1675, New Orleans, Louisiana. sonalized summaries and models. The users in- Association for Computational Linguistics. teract with the model, by entering a source text, selecting different decoding strategies, viewing a Yen Chun Chen and Mohit Bansal. 2018. Fast abstrac- tive summarization with reinforce-selected sentence visualization of the model’s attention and synthe- rewriting. In ACL 2018 - 56th Annual Meeting of sizing a final summary from parts of multiple sum- the Association for Computational Linguistics, Pro- maries, which can be used for further fine-tuning. ceedings of the Conference (Long Papers). We also presented a case study of our work, along Angela Fan, David Grangier, and Michael Auli. 2018a. with a novel dataset, on summarizing financial Controllable abstractive summarization. In Proceed- news. We observed that pre-trained PEGASUS ings of the 2nd Workshop on Neural Machine Trans- models adapt quickly to our dataset, generating lation and Generation, pages 45–54, Melbourne, salient financially-focused summaries. Our work Australia. Association for Computational Linguis- tics. aims to inspire future research in human-centered techniques for neural summarization systems. Angela Fan, Mike Lewis, and Yann Dauphin. 2018b. In future work, human involvement in the sum- Hierarchical neural story generation. In Proceed- ings of the 56th Annual Meeting of the Association marization process could be enhanced by using for Computational Linguistics (Volume 1: Long Pa- approaches that allow users to control different as- pers), pages 889–898, Melbourne, Australia. Asso- pects of the generated summaries, such as length ciation for Computational Linguistics. 25
Jessica Ficler and Yoav Goldberg. 2017. Controlling Conference on Empirical Methods in Natural Lan- linguistic style aspects in neural language genera- guage Processing, pages 1808–1817, Brussels, Bel- tion. In Proceedings of the Workshop on Stylis- gium. Association for Computational Linguistics. tic Variation, pages 94–104, Copenhagen, Denmark. Association for Computational Linguistics. Taku Kudo and John Richardson. 2018. SentencePiece: A simple and language independent subword tok- Asma Ghandeharioun, Judy Hanwen Shen, Natasha enizer and detokenizer for neural text processing. In Jaques, Craig Ferguson, Noah Jones, Àgata Proceedings of the 2018 Conference on Empirical Lapedriza, and Rosalind W. Picard. 2019. Approxi- Methods in Natural Language Processing: System mating interactive human evaluation with self-play Demonstrations, pages 66–71, Brussels, Belgium. for open-domain dialog systems. In Advances in Association for Computational Linguistics. Neural Information Processing Systems 32: Annual Piyawat Lertvittayakumjorn, Lucia Specia, and Conference on Neural Information Processing Sys- Francesca Toni. 2020. FIND: human-in-the-loop tems 2019, NeurIPS 2019, December 8-14, 2019, debugging deep text classifiers. In Proceedings Vancouver, BC, Canada, pages 13658–13669. of the 2020 Conference on Empirical Methods in Natural Language Processing, EMNLP 2020, Kevin Gimpel, Dhruv Batra, Chris Dyer, and Gregory Online, November 16-20, 2020, pages 332–348. Shakhnarovich. 2013. A systematic exploration of Association for Computational Linguistics. diversity in machine translation. In Proceedings of the 2013 Conference on Empirical Methods in Natu- Mike Lewis, Yinhan Liu, Naman Goyal, Mar- ral Language Processing, pages 1100–1111. jan Ghazvininejad, Abdelrahman Mohamed, Omer Levy, Veselin Stoyanov, and Luke Zettlemoyer. Junxian He, Wojciech Kryściński, Bryan McCann, 2020. BART: Denoising sequence-to-sequence pre- Nazneen Rajani, and Caiming Xiong. 2020. Ctrl- training for natural language generation, translation, sum: Towards generic controllable text summariza- and comprehension. In Proceedings of the 58th An- tion. arXiv preprint arXiv:2012.04281. nual Meeting of the Association for Computational Linguistics, pages 7871–7880, Online. Association Karl Moritz Hermann, Tomas Kocisky, Edward Grefen- for Computational Linguistics. stette, Lasse Espeholt, Will Kay, Mustafa Suleyman, and Phil Blunsom. 2015. Teaching machines to read Jiwei Li, Alexander H. Miller, Sumit Chopra, and comprehend. Advances in neural information Marc’Aurelio Ranzato, and Jason Weston. 2016. Di- processing systems, 28:1693–1701. alogue learning with human-in-the-loop. CoRR, abs/1611.09823. Ari Holtzman, Jan Buys, Li Du, Maxwell Forbes, and Yejin Choi. 2020. The curious case of neural text Chin-Yew Lin. 2004. Rouge: A package for automatic degeneration. In 8th International Conference on evaluation of summaries. In Text summarization Learning Representations, ICLR 2020, Addis Ababa, branches out, pages 74–81. Ethiopia, April 26-30, 2020. OpenReview.net. Yang Liu and Mirella Lapata. 2019. Text Summariza- Daphne Ippolito, Reno Kriz, João Sedoc, Maria tion with Pretrained Encoders. In Proceedings of Kustikova, and Chris Callison-Burch. 2019. Com- the 2019 Conference on Empirical Methods in Nat- parison of diverse decoding methods from condi- ural Language Processing and the 9th International tional language models. In Proceedings of the 57th Joint Conference on Natural Language Processing Annual Meeting of the Association for Computa- (EMNLP-IJCNLP), pages 3721–3731. tional Linguistics, pages 3752–3762, Florence, Italy. Yizhu Liu, Zhiyi Luo, and Kenny Zhu. 2018. Con- Association for Computational Linguistics. trolling length in abstractive summarization using a convolutional neural network. In Proceedings of Min-Yen Kan, Kathleen R McKeown, and Judith L Kla- the 2018 Conference on Empirical Methods in Nat- vans. 2001. Domain-specific informative and indica- ural Language Processing, pages 4110–4119, Brus- tive summarization for information retrieval. In In: sels, Belgium. Association for Computational Lin- Workshop on text summarization (DUC 2001. Cite- guistics. seer. Thang Luong, Hieu Pham, and Christopher D. Man- Yuta Kikuchi, Graham Neubig, Ryohei Sasano, Hiroya ning. 2015. Effective approaches to attention-based Takamura, and Manabu Okumura. 2016. Control- neural machine translation. In Proceedings of the ling output length in neural encoder-decoders. In 2015 Conference on Empirical Methods in Natu- Proceedings of the 2016 Conference on Empirical ral Language Processing, pages 1412–1421, Lis- Methods in Natural Language Processing, pages bon, Portugal. Association for Computational Lin- 1328–1338, Austin, Texas. Association for Compu- guistics. tational Linguistics. Ramesh Nallapati, Bowen Zhou, Cicero dos Santos, Wojciech Kryściński, Romain Paulus, Caiming Xiong, Caglar Gülçehre, and Bing Xiang. 2016. Ab- and Richard Socher. 2018. Improving abstraction stractive Text Summarization using Sequence-to- in text summarization. In Proceedings of the 2018 sequence RNNs and Beyond. In Proceedings of The 26
20th SIGNLL Conference on Computational Natural to summarize from human feedback. arXiv preprint Language Learning, pages 280–290, Stroudsburg, arXiv:2009.01325. PA, USA. Association for Computational Linguis- tics. Sho Takase and Naoaki Okazaki. 2019. Positional en- coding to control output sequence length. In Pro- Shashi Narayan, Shay B Cohen, and Mirella Lap- ceedings of the 2019 Conference of the North Amer- ata. 2018. Don’t give me the details, just the ican Chapter of the Association for Computational summary! topic-aware convolutional neural net- Linguistics: Human Language Technologies, Vol- works for extreme summarization. arXiv preprint ume 1 (Long and Short Papers), pages 3999–4004, arXiv:1808.08745. Minneapolis, Minnesota. Association for Computa- tional Linguistics. Colin Raffel, Noam Shazeer, Adam Roberts, Katherine Lee, Sharan Narang, Michael Matena, Yanqi Zhou, Gaurav Trivedi, Phuong Pham, Wendy W. Chapman, Wei Li, and Peter J. Liu. 2020a. Exploring the limits Rebecca Hwa, Janyce Wiebe, and Harry Hochheiser. of transfer learning with a unified text-to-text trans- 2018. Nlpreviz: an interactive tool for natural lan- former. J. Mach. Learn. Res., 21:140:1–140:67. guage processing on clinical text. J. Am. Medical Informatics Assoc., 25(1):81–87. Colin Raffel, Noam Shazeer, Adam Roberts, Kather- ine Lee, Sharan Narang, Michael Matena, Yanqi Shikhar Vashishth, Shyam Upadhyay, Gaurav Singh Zhou, Wei Li, and Peter J. Liu. 2020b. Exploring Tomar, and Manaal Faruqui. 2019. Attention inter- the limits of transfer learning with a unified text-to- pretability across nlp tasks. arXiv. text transformer. Journal of Machine Learning Re- search, 21(140):1–67. Ashish Vaswani, Noam Shazeer, Niki Parmar, Jakob Uszkoreit, Llion Jones, Aidan N Gomez, Łukasz Lawrence H Reeve, Hyoil Han, and Ari D Brooks. Kaiser, and Illia Polosukhin. 2017. Attention is all 2007. The use of domain-specific concepts in you need. In Advances in neural information pro- biomedical text summarization. Information Pro- cessing systems, pages 5998–6008. cessing & Management, 43(6):1765–1776. Jesse Vig and Yonatan Belinkov. 2019. Analyzing Abigail See, Peter J Liu, and Christopher D Man- the structure of attention in a transformer language ning. 2017. Get To The Point: Summarization with model. In Proceedings of the 2019 ACL Workshop Pointer-Generator Networks. In Proceedings of the BlackboxNLP: Analyzing and Interpreting Neural 2017 Annual Meeting of the Association for Compu- Networks for NLP, pages 63–76, Florence, Italy. As- tational Linguistics, pages 1073–1083. sociation for Computational Linguistics. Sofia Serrano and Noah A. Smith. 2019. Is attention Ashwin K Vijayakumar, Michael Cogswell, Ram- interpretable? In Proceedings of the 57th Annual prasath R Selvaraju, Qing Sun, Stefan Lee, David Meeting of the Association for Computational Lin- Crandall, and Dhruv Batra. 2016. Diverse beam guistics, pages 2931–2951, Florence, Italy. Associa- search: Decoding diverse solutions from neural se- tion for Computational Linguistics. quence models. arXiv preprint arXiv:1610.02424. Yuanlong Shao, Stephan Gouws, Denny Britz, Anna Jingqing Zhang, Yao Zhao, Mohammad Saleh, and Pe- Goldie, Brian Strope, and Ray Kurzweil. 2017. Gen- ter Liu. 2020. Pegasus: Pre-training with extracted erating high-quality and informative conversation re- gap-sentences for abstractive summarization. In In- sponses with sequence-to-sequence models. In Pro- ternational Conference on Machine Learning, pages ceedings of the 2017 Conference on Empirical Meth- 11328–11339. PMLR. ods in Natural Language Processing, pages 2210– 2219, Copenhagen, Denmark. Association for Com- putational Linguistics. Ori Shapira, Hadar Ronen, Meni Adler, Yael Amster- damer, Judit Bar-Ilan, and Ido Dagan. 2017. Interac- tive abstractive summarization for event news tweets. In Proceedings of the 2017 Conference on Empirical Methods in Natural Language Processing: System Demonstrations, pages 109–114, Copenhagen, Den- mark. Association for Computational Linguistics. Shengli Song, Haitao Huang, and Tongxiao Ruan. 2019. Abstractive text summarization using lstm- cnn based deep learning. Multimedia Tools and Ap- plications, 78. Nisan Stiennon, Long Ouyang, Jeff Wu, Daniel M Ziegler, Ryan Lowe, Chelsea Voss, Alec Radford, Dario Amodei, and Paul Christiano. 2020. Learning 27
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