In this paper, we present AILS-NTUA system for Track-A of SemEval-2026 Task 3 on Dimensional Aspect-Based Sentiment Analysis (DimABSA), which encompasses three complementary problems: Dimensional Aspect Sentiment Regression (DimASR), Dimensional Aspect Sentiment Triplet Extraction (DimASTE), and Dimensional Aspect Sentiment Quadruplet Prediction (DimASQP) within a multilingual and multi-domain framework. Our methodology combines fine-tuning of language-appropriate encoder backbones for continuous aspect-level sentiment prediction with language-specific instruction tuning of large language models using LoRA for structured triplet and quadruplet extraction. This unified yet task-adaptive design emphasizes parameter-efficient specialization across languages and domains, enabling reduced training and inference requirements while maintaining strong effectiveness. Empirical results demonstrate that the proposed models achieve competitive performance and consistently surpass the provided baselines across most evaluation settings.
Figures & tables
Lang.
Domain
Dev
Test
RMSE VA ↓
PCC V ↑
PCC A ↑
RMSE VA ↓
PCC V ↑
PCC A ↑
ENG
Laptop
1.0166
0.9174
0.5768
1.4401
0.8520
0.5073
Restaurant
0.9208
0.9295
0.6882
1.3933
0.8757
0.6105
ZHO
Finance
0.5438
0.8241
0.5981
0.5425
0.8327
0.6436
Laptop
0.7443
0.8863
0.7042
0.7457
0.8738
0.7133
Restaurant
0.8007
0.8419
0.6748
1.0023
0.8258
0.5852
Table 1: DimASR results per language and domain.
Lang.
Model
Domain
cF1 ↑
Dev
Test
ENG
Llama 3.1 8B
Laptop
0.5962
0.5311
Restaurant
0.7668
0.6518
ZHO
Qwen 2.5 7B
Laptop
0.4193
0.4646
Restaurant
0.5916
0.5042
JPN
Qwen 2.5 14B
Hotel
0.4879
0.5021
Table 2: DimASTE results per language and domain.
Lang.
Model
Domain
cF1 ↑
Dev
Test
ENG
Llama 3.1 8B
Laptop
0.3556
0.2694
Restaurant
0.7560
0.5988
ZHO
Qwen 2.5 7B
Laptop
0.3662
0.3703
Restaurant
0.5665
0.4544
JPN
Qwen 2.5 14B
Hotel
0.4218
0.3747
Table 3: DimASQP results per language and domain.
Lang.
Translate+Train
ENG-Model
ZHO
0.36
0.26
RUS
0.31
0.31
UKR
0.24
0.25
TAT
0.20
0.22
Table 4: Restaurant DimASQP (cF1), Dev set, Llama 3.1 8B: translation training vs. English-trained model.
Appendix figures & tables12 assets
Supplementary material from the paper’s appendix.
Appendix
Subtask
Example (JSON)
DimASR
{"ID": "rest26_aspect_va_dev_1", "Text": "Great diner food and breakfast is served all day", "Aspect_VA": [{"Aspect": "diner food", "VA": "7.25#6.75"}, {"Aspect": "breakfast", "VA": "7.25#6.75"}]}
DimASTE
{"ID": "rest26_aste_dev_2", "Text": "Customer service was fantastic and food was awesome", "Triplet": [{"Aspect": "Customer service", "Opinion": "fantastic", "VA": "7.33#7.33"}, {"Aspect": "food", "Opinion": "awesome", "VA": "7.67#7.67"}]}
Table 10: DimASTE Dev set results in zero-shot and few-shot prompting (cF1) using Qwen 2.5 14B Instruct.
Lang.
Domain
Dev cF1 ↑
Zero-shot
Few-shot
ENG
Laptop
0.22
0.32
Restaurant
0.42
0.51
ZHO
Laptop
0.14
0.18
Restaurant
0.23
0.31
JPN
Hotel
0.06
0.11
Appendix
Table 11: DimASQP Dev set results in zero-shot and few-shot prompting (cF1) using Qwen 2.5 14B Instruct.
Lang.
Model
Domain
Dev cF1 ↑
ENG
Llama 3.1 70B
Laptop
0.3373
Restaurant
0.7441
ZHO
Qwen 2.5 32B
Laptop
0.3119
Restaurant
0.5220
Qwen 2.5 72B
Laptop
0.3675
Restaurant
0.5508
Appendix
Table 12: DimASQP development set results (cF1) after lora-tuning larger LLMs.
Figure 1: DimASR dataset statistics across splits: number of reviews (left) and aspects per review (right).
Figure 2: DimASTE and DimASQP dataset statistics across splits: number of reviews (left) and quadruplets per review (right).
Figure 3: DimASTE and DimASQP NULL analysis on Train set: NULL rate (left) and composition of NULL cases (right).
Figure 4: DimASTE and DimASQP distribution shift measured by PSI between Train and Dev/Test across features (review length, quadruplets/review, and category).
This paper describes our system to SemEval-2026 Task 3 Track A Subtask 1 on Dimensional Aspect Sentiment Regression (DimASR). We propose a lightweight and resource-efficient system built entirely on multilingual pre-trained encoders, without relying on LLMs or external corpora. We adopt joint multilingual and multi-domain training to facilitate cross-lingual transfer and alleviate data sparsity, introduce a bounded regression transformation that improves training stability while constraining predictions within the valid range, and employ an adaptive ensemble strategy via subset search to reduce prediction variance. Experimental results demonstrate that our system achieves strong and consistent performance, ranking 1st on zho-res, 2nd on zho-lap, and 3rd on jpn-hot, with all remaining datasets placed within the top half of participating teams.
Liyuan Huang, Jiawei He, Wutao Shen +2
1State Key Laboratory of AI Safety · Institute of Computing Technology, Chinese Academy of Sciences · University of Chinese Academy of Sciences
Dimensional Aspect-Based Sentiment Analysis (DimABSA) extends traditional ABSA from categorical polarity labels to continuous valence-arousal (VA) regression. This paper describes a system developed for Track A, Subtask 1 (Dimensional Aspect Sentiment Regression), aiming to predict real-valued VA scores in the [1, 9] range for each given aspect in a text. A fine-tuning approach based on XLM-RoBERTa-base is adopted, with dual regression heads with sigmoid-scaled outputs for valence and arousal prediction. Separate models are trained for each language-domain pair (English and Chinese across restaurant, laptop, and finance domains), and training and development sets are merged for final test predictions. In development experiments, the fine-tuning approach is compared against several large language models under a few-shot prompting setting, demonstrating that task-specific fine-tuning outperforms these LLM-based methods across all evaluation datasets.
Tong Wu, Nicolay Rusnachenko, Huizhi Liang
Independent Researcher · Centre for Applied Creative Technologies (CFACT+), Bournemouth University, UK · School of Computing, Newcastle University, Newcastle upon Tyne, UK
We present our system for SemEval-2026 Task 3 on dimensional aspect-based sentiment regression. Our approach combines a hybrid RoBERTa encoder, which jointly predicts sentiment using regression and discretized classification heads, with large language models (LLMs) via prediction-level ensemble learning. The hybrid encoder improves prediction stability by combining continuous and discretized sentiment representations. We further explore in-context learning with LLMs and ridge-regression stacking to combine encoder and LLM predictions. Experimental results on the development set show that ensemble learning significantly improves performance over individual models, achieving substantial reductions in RMSE and improvements in correlation scores. Our findings demonstrate the complementary strengths of encoder-based and LLM-based approaches for dimensional sentiment analysis. Our development code and resources will be shared at https://github.com/aaronlifenghan/ABSentiment
A. J. W. de Vink, Filippos Karolos Ventirozos, Natalia Amat-Lefort +1
LIACS, Leiden University, NL · Manchester Metropolitan University, UK · Leiden University Medical Center, NL