Subscribe to the gold package and get unlimited access to Shamra Academy
Register a new userSensitivity as a Complexity Measure for Sequence Classification Tasks
الحساسية كتدبير تعقيد لمهام تصنيف التسلسل
650
0 0
0.0
(
0
)
Created by
Shamra Editor
Ask ChatGPT about the research
الملخص نقدم إطارا نظري لفهم وتوقع تعقيد مهام تصنيف التسلسل، باستخدام تمديد جديد لنظرية حساسية وظيفة المنطقية. حساسية الوظيفة، نظرا للتوزيع على تسلسل الإدخال، يحدد عدد الفك القصير من تسلسل الإدخال الذي يمكن تغيير كل منهما بشكل فردي لتغيير الإخراج. نقول أن أساليب تصنيف التسلسل القياسية متحيزة نحو تعلم وظائف الحساسية المنخفضة، بحيث تكون المهام التي تتطلب حساسية عالية أكثر صعوبة. تحقيقا لهذه الغاية، نظهر تحليليا أن المصنفات المعجمية البسيطة يمكن أن تعبر فقط عن وظائف الحساسية المحددة، ونظرا تجريبيا أن وظائف الحساسية المنخفضة هي أسهل للتعلم من أجل LSTMS. ثم نقدر الحساسية في 15 مهام NLP، ويجد أن الحساسية أعلى على المهام الصعبة التي تم جمعها في الغراء أكثر من مهام تصنيف النص البسيطة، وأن الحساسية تتنبأ بأداء كل من المصنفات المعجمية البسيطة والفانيليا BILSTMS دون إشارة إلى تضمينات محاط بأذى. في غضون مهمة، تتوقع الحساسية المدخلات من الصعب على هذه النماذج البسيطة. تشير نتائجنا إلى أن نجاح التمثيلات السياقية المسبقة بشكل كبير ينبع جزئيا لأنهم يقدمون تمثيلات يمكن استخراج المعلومات من خلال فك رموز حساسية منخفضة الحساسية.
Abstract We introduce a theoretical framework for understanding and predicting the complexity of sequence classification tasks, using a novel extension of the theory of Boolean function sensitivity. The sensitivity of a function, given a distribution over input sequences, quantifies the number of disjoint subsets of the input sequence that can each be individually changed to change the output. We argue that standard sequence classification methods are biased towards learning low-sensitivity functions, so that tasks requiring high sensitivity are more difficult. To that end, we show analytically that simple lexical classifiers can only express functions of bounded sensitivity, and we show empirically that low-sensitivity functions are easier to learn for LSTMs. We then estimate sensitivity on 15 NLP tasks, finding that sensitivity is higher on challenging tasks collected in GLUE than on simple text classification tasks, and that sensitivity predicts the performance both of simple lexical classifiers and of vanilla BiLSTMs without pretrained contextualized embeddings. Within a task, sensitivity predicts which inputs are hard for such simple models. Our results suggest that the success of massively pretrained contextual representations stems in part because they provide representations from which information can be extracted by low-sensitivity decoders.
References used
https://aclanthology.org/
rate research
Read More
This paper studies continual learning (CL) of a sequence of aspect sentiment classification (ASC) tasks. Although some CL techniques have been proposed for document sentiment classification, we are not aware of any CL work on ASC. A CL system that in
crementally learns a sequence of ASC tasks should address the following two issues: (1) transfer knowledge learned from previous tasks to the new task to help it learn a better model, and (2) maintain the performance of the models for previous tasks so that they are not forgotten. This paper proposes a novel capsule network based model called B-CL to address these issues. B-CL markedly improves the ASC performance on both the new task and the old tasks via forward and backward knowledge transfer. The effectiveness of B-CL is demonstrated through extensive experiments.
Challenging problems such as open-domain question answering, fact checking, slot filling and entity linking require access to large, external knowledge sources. While some models do well on individual tasks, developing general models is difficult as
each task might require computationally expensive indexing of custom knowledge sources, in addition to dedicated infrastructure. To catalyze research on models that condition on specific information in large textual resources, we present a benchmark for knowledge-intensive language tasks (KILT). All tasks in KILT are grounded in the same snapshot of Wikipedia, reducing engineering turnaround through the re-use of components, as well as accelerating research into task-agnostic memory architectures. We test both task-specific and general baselines, evaluating downstream performance in addition to the ability of the models to provide provenance. We find that a shared dense vector index coupled with a seq2seq model is a strong baseline, outperforming more tailor-made approaches for fact checking, open-domain question answering and dialogue, and yielding competitive results on entity linking and slot filling, by generating disambiguated text. KILT data and code are available at https://github.com/facebookresearch/KILT.
End-to-end approaches for sequence tasks are becoming increasingly popular. Yet for complex sequence tasks, like speech translation, systems that cascade several models trained on sub-tasks have shown to be superior, suggesting that the compositional
ity of cascaded systems simplifies learning and enables sophisticated search capabilities. In this work, we present an end-to-end framework that exploits compositionality to learn searchable hidden representations at intermediate stages of a sequence model using decomposed sub-tasks. These hidden intermediates can be improved using beam search to enhance the overall performance and can also incorporate external models at intermediate stages of the network to re-score or adapt towards out-of-domain data. One instance of the proposed framework is a Multi-Decoder model for speech translation that extracts the searchable hidden intermediates from a speech recognition sub-task. The model demonstrates the aforementioned benefits and outperforms the previous state-of-the-art by around +6 and +3 BLEU on the two test sets of Fisher-CallHome and by around +3 and +4 BLEU on the English-German and English-French test sets of MuST-C.
Multi-label emotion classification is an important task in NLP and is essential to many applications. In this work, we propose a sequence-to-emotion (Seq2Emo) approach, which implicitly models emotion correlations in a bi-directional decoder. Experim
ents on SemEval'18 and GoEmotions datasets show that our approach outperforms state-of-the-art methods (without using external data). In particular, Seq2Emo outperforms the binary relevance (BR) and classifier chain (CC) approaches in a fair setting.
Prior methods to text segmentation are mostly at token level. Despite the adequacy, this nature limits their full potential to capture the long-term dependencies among segments. In this work, we propose a novel framework that incrementally segments n
atural language sentences at segment level. For every step in segmentation, it recognizes the leftmost segment of the remaining sequence. Implementations involve LSTM-minus technique to construct the phrase representations and recurrent neural networks (RNN) to model the iterations of determining the leftmost segments. We have conducted extensive experiments on syntactic chunking and Chinese part-of-speech (POS) tagging across 3 datasets, demonstrating that our methods have significantly outperformed previous all baselines and achieved new state-of-the-art results. Moreover, qualitative analysis and the study on segmenting long-length sentences verify its effectiveness in modeling long-term dependencies.
suggested questions
Log in to be able to interact and post comments
comments
Fetching comments
Sign in to be able to follow your search criteria
