Dialogue Aspect-based Sentiment Quadruple (DiaASQ) analysis aims to identify all quadruples (i.e., target, aspect, opinion, sentiment) from the dialogue. This task is challenging as different elements within a quadruple may manifest in different utterances, requiring precise handling of associations at both the utterance and word levels. However, most existing methods tackling it predominantly leverage predefined dialogue structure (e.g., reply) and word semantics, resulting in a surficial understanding of the deep sentiment association between utterances and words. In this paper, we propose a novel Multi-level Association Refinement Network (MARN) designed to achieve more accurate and comprehensive sentiment associations between utterances and words. Specifically, for utterances, we dynamically capture their associations with enriched semantic features through a holistic understanding of the dialogue, aligning them more closely with sentiment associations within elements in quadruples. For words, we develop a novel cross-utterance syntax parser (CU-Parser) that fully exploits syntactic information to enhance the association between word pairs within and across utterances. Moreover, to address the scarcity of labeled data in DiaASQ, we further introduce a multi-view data augmentation strategy to enhance the performance of MARN under low-resource conditions. Experimental results demonstrate that MARN achieves state-of-the-art performance and maintains robustness even under low-resource conditions.

Large language models (LLMs) possess extensive prior knowledge and powerful in-context learning (ICL) capabilities, presenting significant opportunities for low-resource tasks. Though effective, several key issues still have not been well-addressed when focusing on zero-shot named entity recognition (NER), including the misalignment between model and human definitions of entity types, and confusion of similar types. This paper proposes an Evolving Prompts framework that guides the model to better address these issues through continuous prompt refinement. Specifically, we leverage the model to summarize the definition of each entity type and the distinctions between similar types (i.e., entity type guidelines). An iterative process is introduced to continually adjust and improve these guidelines. Additionally, since high-quality demonstrations are crucial for effective learning yet challenging to obtain in zero-shot scenarios, we design a strategy motivated by self-consistency and prototype learning to extract reliable and diverse pseudo samples from the model’s predictions. Experiments on four benchmarks demonstrate the effectiveness of our framework, showing consistent performance improvements.

This paper describes our system and findings for SIGHAN-2024 Shared Task Chinese Dimensional Aspect-Based Sentiment Analysis (dimABSA). Our team CCIIPLab proposes an Contrastive Learning-Enhanced Span-based (CL-Span) framework to boost the performance of extracting triplets/quadruples and predicting sentiment intensity. We first employ a span-based framework that integrates contextual representations and incorporates rotary position embedding. This approach fully considers the relational information of entire aspect and opinion terms, and enhancing the model’s understanding of the associations between tokens. Additionally, we utilize contrastive learning to predict sentiment intensities in the valence-arousal dimensions with greater precision. To improve the generalization ability of the model, additional datasets are used to assist training. Experiments have validated the effectiveness of our approach. In the official test results, our system ranked 2nd among the three subtasks.