Improving Concept Alignment in Vision-Language Concept Bottleneck Models

Fuente: arXiv
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Main Authors: Selvaraj, Nithish Muthuchamy, Guo, Xiaobao, Kong, Adams Wai-Kin, Kot, Alex
Format: Preprint
Published: 2024
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author Selvaraj, Nithish Muthuchamy
Guo, Xiaobao
Kong, Adams Wai-Kin
Kot, Alex
author_facet Selvaraj, Nithish Muthuchamy
Guo, Xiaobao
Kong, Adams Wai-Kin
Kot, Alex
contents Concept Bottleneck Models (CBM) map images to human-interpretable concepts before making class predictions. Recent approaches automate CBM construction by prompting Large Language Models (LLMs) to generate text concepts and employing Vision Language Models (VLMs) to score these concepts for CBM training. However, it is desired to build CBMs with concepts defined by human experts rather than LLM-generated ones to make them more trustworthy. In this work, we closely examine the faithfulness of VLM concept scores for such expert-defined concepts in domains like fine-grained bird species and animal classification. Our investigations reveal that VLMs like CLIP often struggle to correctly associate a concept with the corresponding visual input, despite achieving a high classification performance. This misalignment renders the resulting models difficult to interpret and less reliable. To address this issue, we propose a novel Contrastive Semi-Supervised (CSS) learning method that leverages a few labeled concept samples to activate truthful visual concepts and improve concept alignment in the CLIP model. Extensive experiments on three benchmark datasets demonstrate that our method significantly enhances both concept (+29.95) and classification (+3.84) accuracies yet requires only a fraction of human-annotated concept labels. To further improve the classification performance, we introduce a class-level intervention procedure for fine-grained classification problems that identifies the confounding classes and intervenes in their concept space to reduce errors.
format Preprint
id arxiv_https___arxiv_org_abs_2405_01825
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Improving Concept Alignment in Vision-Language Concept Bottleneck Models
Selvaraj, Nithish Muthuchamy
Guo, Xiaobao
Kong, Adams Wai-Kin
Kot, Alex
Computer Vision and Pattern Recognition
Concept Bottleneck Models (CBM) map images to human-interpretable concepts before making class predictions. Recent approaches automate CBM construction by prompting Large Language Models (LLMs) to generate text concepts and employing Vision Language Models (VLMs) to score these concepts for CBM training. However, it is desired to build CBMs with concepts defined by human experts rather than LLM-generated ones to make them more trustworthy. In this work, we closely examine the faithfulness of VLM concept scores for such expert-defined concepts in domains like fine-grained bird species and animal classification. Our investigations reveal that VLMs like CLIP often struggle to correctly associate a concept with the corresponding visual input, despite achieving a high classification performance. This misalignment renders the resulting models difficult to interpret and less reliable. To address this issue, we propose a novel Contrastive Semi-Supervised (CSS) learning method that leverages a few labeled concept samples to activate truthful visual concepts and improve concept alignment in the CLIP model. Extensive experiments on three benchmark datasets demonstrate that our method significantly enhances both concept (+29.95) and classification (+3.84) accuracies yet requires only a fraction of human-annotated concept labels. To further improve the classification performance, we introduce a class-level intervention procedure for fine-grained classification problems that identifies the confounding classes and intervenes in their concept space to reduce errors.
title Improving Concept Alignment in Vision-Language Concept Bottleneck Models
topic Computer Vision and Pattern Recognition
url https://arxiv.org/abs/2405.01825