COSMic: A Coherence-Aware Generation Metric for Image Descriptions

Mert Inan, Piyush Sharma, Baber Khalid, Radu Soricut, Matthew Stone, Malihe Alikhani


Abstract
Developers of text generation models rely on automated evaluation metrics as a stand-in for slow and expensive manual evaluations. However, image captioning metrics have struggled to give accurate learned estimates of the semantic and pragmatic success of output text. We address this weakness by introducing the first discourse-aware learned generation metric for evaluating image descriptions. Our approach is inspired by computational theories of discourse for capturing information goals using coherence. We present a dataset of image–description pairs annotated with coherence relations. We then train a coherence-aware metric on a subset of the Conceptual Captions dataset and measure its effectiveness—its ability to predict human ratings of output captions—on a test set composed of out-of-domain images. We demonstrate a higher Kendall Correlation Coefficient for our proposed metric with the human judgments for the results of a number of state-of-the-art coherence-aware caption generation models when compared to several other metrics including recently proposed learned metrics such as BLEURT and BERTScore.
Anthology ID:
2021.findings-emnlp.291
Volume:
Findings of the Association for Computational Linguistics: EMNLP 2021
Month:
November
Year:
2021
Address:
Punta Cana, Dominican Republic
Venue:
Findings
SIG:
SIGDAT
Publisher:
Association for Computational Linguistics
Note:
Pages:
3419–3430
Language:
URL:
https://aclanthology.org/2021.findings-emnlp.291
DOI:
10.18653/v1/2021.findings-emnlp.291
Bibkey:
Cite (ACL):
Mert Inan, Piyush Sharma, Baber Khalid, Radu Soricut, Matthew Stone, and Malihe Alikhani. 2021. COSMic: A Coherence-Aware Generation Metric for Image Descriptions. In Findings of the Association for Computational Linguistics: EMNLP 2021, pages 3419–3430, Punta Cana, Dominican Republic. Association for Computational Linguistics.
Cite (Informal):
COSMic: A Coherence-Aware Generation Metric for Image Descriptions (Inan et al., Findings 2021)
Copy Citation:
PDF:
https://aclanthology.org/2021.findings-emnlp.291.pdf
Software:
 2021.findings-emnlp.291.Software.zip
Video:
 https://aclanthology.org/2021.findings-emnlp.291.mp4
Code
 merterm/cosmic
Data
Conceptual Captions