Question: Why did the researchers increase the interest and improve the performance of abstractive summarization?
Evidence: Abstractive Summarization. Abstractive summarization aims to generate coherent summaries with high readability, and has seen increasing interest and improved performance due to the emergence of seq2seq models BIBREF8 and attention mechanisms BIBREF9. For example, BIBREF0, BIBREF2, and BIBREF1 in addition to using encoder-decoder model with attention, they used pointer networks to solve the out of vocabulary issue, while BIBREF0 used coverage mechanism to solve the problem of word repetition. In addition, BIBREF2 and BIBREF10 used reinforcement learning in an end-to-end setting.
To our knowledge, training such neural abstractive summarization models in low resource domains using domain transfer has not been thoroughly explored on domains different than news. For example, BIBREF4 reported the results of training on CNN/DM data while evaluating on DUC data without any tuning. Note that these two datasets are both in the news domain, and both consist of well written, structured documents. The domain transfer experiments of BIBREF1 similarly used two different news summarization datasets (CNN/DM and NYT). Our work differs in several ways from these two prior domain transfer efforts. First, our experiments involve two entirely different domains: news and student reflections. Unlike news, student reflection documents lack global structure, are repetitive, and contain many sentence fragments and grammatical mistakes. Second, the prior approaches either trained a part of the model using NYT data while retaining the other part of the model trained only on CNN/DM data BIBREF1, or didn't perform any tuning at all BIBREF4. In contrast, we do the training in two consecutive phases, pretraining and fine tuning. Finally, BIBREF1 reported that while training with domain transfer outperformed training only on out-of-domain data, it was not able to beat training only on in-domain data. This is likely because their in and out-of-domain data sizes are comparable, unlike in our case of scarce in-domain data.
In a different approach to abstractive summarization, BIBREF11 developed a soft template based neural method consisting of an end-to-end deep model for template retrieval, reranking and summary rewriting. While we also develop a template based model, our work differs in both model structure and purpose.
Data Synthesis. Data synthesis for text summarization is underexplored, with most prior work focusing on machine translation, and text normalization. BIBREF12 proposed doing data augmentation through word replacement, using WordNet BIBREF13 and vector space similarity, respectively. We will use a WordNet replacement method as a baseline synthesis method in the experiments described below. In contrast, BIBREF14 synthesized/augmented data through back-translation and word replacement using language models. BIBREF15 is another recent work that was done in parallel and is very close to ours. However, in addition to the difference in both our and their model, we think it might be infeasible to back generate student reflections from a human summary, especially an abstractive one.
Abstractive summarization aims to generate coherent summaries with high readability, and has seen increasing interest and improved performance due to the emergence of seq2seq models (Sutskever, Vinyals, and Le 2014) and attention mechanisms (Bahdanau, Cho, and Bengio 2014).
Answer: Because the emergence of seq2seq models and attention mechanisms.