OpinSummEval: Revisiting Automated Evaluation for Opinion Summarization
Yuchen Shen, Xiaojun Wan
TL;DR
Opinion summarization requires extracting salient aspects and sentiments from noisy reviews, posing unique evaluation challenges. This work introduces OpinSummEval, a human-annotated benchmark across 14 models and 4 evaluation dimensions to study metric correlations, and comprehensively analyzes 26 automatic metrics. The findings show neural-based metrics generally outperform traditional overlap metrics like ROUGE, though even strong backbones such as BART and GPT-3.5 do not consistently align with human judgments across all dimensions; reference-free neural metrics tend to perform well. The paper highlights gaps in current automated evaluation for opinion summarization and advocates for QA-based and input-output matching paradigms, along with development of domain-specific metrics to advance the field.
Abstract
Opinion summarization sets itself apart from other types of summarization tasks due to its distinctive focus on aspects and sentiments. Although certain automated evaluation methods like ROUGE have gained popularity, we have found them to be unreliable measures for assessing the quality of opinion summaries. In this paper, we present OpinSummEval, a dataset comprising human judgments and outputs from 14 opinion summarization models. We further explore the correlation between 24 automatic metrics and human ratings across four dimensions. Our findings indicate that metrics based on neural networks generally outperform non-neural ones. However, even metrics built on powerful backbones, such as BART and GPT-3/3.5, do not consistently correlate well across all dimensions, highlighting the need for advancements in automated evaluation methods for opinion summarization. The code and data are publicly available at https://github.com/A-Chicharito-S/OpinSummEval/tree/main.
