Hierarchical Attention: What Really Counts in Various NLP Tasks
Attention mechanisms in sequence to sequence models have shown great ability and wonderful performance in various natural language processing (NLP) tasks, such as sentence embedding, text generation, machine translation, machine reading comprehension, etc. Unfortunately, existing attention mechanisms only learn either high-level or low-level features. In this paper, we think that the lack of hierarchical mechanisms is a bottleneck in improving the performance of the attention mechanisms, and propose a novel Hierarchical Attention Mechanism (Ham) based on the weighted sum of different layers of a multi-level attention. Ham achieves a state-of-the-art BLEU score of 0.26 on Chinese poem generation task and a nearly 6.5% averaged improvement compared with the existing machine reading comprehension models such as BIDAF and Match-LSTM. Furthermore, our experiments and theorems reveal that Ham has greater generalization and representation ability than existing attention mechanisms.
 The paper introduces hierarchical attention, where they propose to weighted combine all the intermediate layers of multi-level attention. The idea is simple and seems to be promising, however originality seems incremental. In order to fully demonstrate the significance of the proposed algorithm, the authors should conduct more comparisons, for example, to multi-level attention. Just comparing with one-level attention seems unfair given the significant increase of computation. Another aspect of comparison may be to consider computation and performance improvements together and discuss the best trade-off. The authors should also include some standard benchmark datasets for comparisons. The current ones are good but it is not so clear what is the best state-of-the-arts results on them when compared with all other methods. The analysis on the network*s representation and convergence is nice but it does not bring much insights. The argument for decreasing global minimal of the loss function in terms of increasing parameter size can be made for nearly all models but it is of little practical use since there is no guarantee one can reach the global optimal of these models. I recommend the authors to analyze/demonstrate how effective this weighted combination is. For example, the paper can benefit from some clear examples that show the learned weights across the layers and which ones are more important. The presentation of the paper needs some polishing. For example, there are numerous typos, grammatical errors everywhere.
You are a member of the scientific community tasked with peer review. Review the following paper title and abstract.
### Title + Abstract
Hierarchical Attention: What Really Counts in Various NLP Tasks
Attention mechanisms in sequence to sequence models have shown great ability and wonderful performance in various natural language processing (NLP) tasks, such as sentence embedding, text generation, machine translation, machine reading comprehension, etc. Unfortunately, existing attention mechanisms only learn either high-level or low-level features. In this paper, we think that the lack of hierarchical mechanisms is a bottleneck in improving the performance of the attention mechanisms, and propose a novel Hierarchical Attention Mechanism (Ham) based on the weighted sum of different layers of a multi-level attention. Ham achieves a state-of-the-art BLEU score of 0.26 on Chinese poem generation task and a nearly 6.5% averaged improvement compared with the existing machine reading comprehension models such as BIDAF and Match-LSTM. Furthermore, our experiments and theorems reveal that Ham has greater generalization and representation ability than existing attention mechanisms.
user
<think>Okay, to do a decent peer review, I should start with summarizing what the work is about. This includes novelty, contributions, clarity, and impact. I might include suggestions to issues that I find critical to the usefulness of the work. Starting with novelty, there are different types of novelty. The first aspect of novelty is scope and scale. Is the work covering a broader perspective than previous works? The second aspect is methodology. Is the proposed methodology novel compared to previous methods? Do they provide any significant advantage over previous methodologies? The third aspect is results. Are the results different compared previous work? Does this lead to any novel theories or an extension of current theories? Next is clarity, I will be reading the work in depth and analyze if any sentences can be potentially ambiguous or misleading. If any sentences are ambiguous, I will state them and give a suggestion on how to rephrase such sentence or how to make more clear to the audience. Lastly, impact is important. I will attempt to predict how such work will impact the scientific community. This might include the applications of such work and how the work might transform the way we study a certain topic. Finally, I will might only mention issues that are critical. This is to keep the review as concise and helpful as possible.</think>



 The paper introduces hierarchical attention, where they propose to weighted combine all the intermediate layers of multi-level attention. The idea is simple and seems to be promising, however originality seems incremental. In order to fully demonstrate the significance of the proposed algorithm, the authors should conduct more comparisons, for example, to multi-level attention. Just comparing with one-level attention seems unfair given the significant increase of computation. Another aspect of comparison may be to consider computation and performance improvements together and discuss the best trade-off. The authors should also include some standard benchmark datasets for comparisons. The current ones are good but it is not so clear what is the best state-of-the-arts results on them when compared with all other methods. The analysis on the network*s representation and convergence is nice but it does not bring much insights. The argument for decreasing global minimal of the loss function in terms of increasing parameter size can be made for nearly all models but it is of little practical use since there is no guarantee one can reach the global optimal of these models. I recommend the authors to analyze/demonstrate how effective this weighted combination is. For example, the paper can benefit from some clear examples that show the learned weights across the layers and which ones are more important. The presentation of the paper needs some polishing. For example, there are numerous typos, grammatical errors everywhere.
assistant
 The paper introduces hierarchical attention, where they propose to weighted combine all the intermediate layers of multi-level attention. The idea is simple and seems to be promising, however originality seems incremental. In order to fully demonstrate the significance of the proposed algorithm, the authors should conduct more comparisons, for example, to multi-level attention. Just comparing with one-level attention seems unfair given the significant increase of computation. Another aspect of comparison may be to consider computation and performance improvements together and discuss the best trade-off. The authors should also include some standard benchmark datasets for comparisons. The current ones are good but it is not so clear what is the best state-of-the-arts results on them when compared with all other methods. The analysis on the network*s representation and convergence is nice but it does not bring much insights. The argument for decreasing global minimal of the loss function in terms of increasing parameter size can be made for nearly all models but it is of little practical use since there is no guarantee one can reach the global optimal of these models. I recommend the authors to analyze/demonstrate how effective this weighted combination is. For example, the paper can benefit from some clear examples that show the learned weights across the layers and which ones are more important. The presentation of the paper needs some polishing. For example, there are numerous typos, grammatical errors everywhere.