DiaVLo: Diagnosing Behaviours of Vision-Language Models

TL;DR

DiaVLo framework diagnoses vision-language model behaviors using human curation and generation capabilities, revealing potential misalignments.

cs.CL 🟡 Intermediate 2026-09-19 22 views
Lorenzo Corti Jie Yang
vision-language models behavior diagnosis causal estimation model alignment open datasets

Key Findings

Methodology

DiaVLo framework combines human curation and model generation capabilities to define expected and observed behaviors, using causal modeling to quantify visual concept influences. Scene graph generation with IETrans is verified and expanded by humans. Models self-explain to generate REALLY-KNOWs, with causal effects estimated using double machine learning.

Key Results

  • DiaVLo tested on four open-source VLMs and multiple datasets, behavior labels correlate with model performance.
  • Reveals patterns in concept perception, organization, and prioritization.
  • Provides behavior labels to contextualize model performance.

Significance

DiaVLo offers a systematic approach for diagnosing VLM behaviors, helping identify model consistency and potential biases in multimodal tasks. This is crucial for academia and industry as it enhances model reliability and transparency.

Technical Contribution

DiaVLo introduces a novel way to diagnose VLM behaviors through causal modeling and self-explanation. Compared to existing methods, DiaVLo not only identifies behavioral inconsistencies but also quantifies the impact of visual concepts on outputs.

Novelty

DiaVLo uniquely combines human curation with causal modeling to systematically diagnose VLM behaviors, offering new behavior classification standards and causal effect estimation methods.

Limitations

  • DiaVLo relies on human curation, which may introduce subjective bias.
  • The accuracy of model self-explanations needs verification.
  • The complexity of causal modeling may limit its application on large-scale datasets.

Future Work

Future work could include automating the human curation process, improving the accuracy of self-explanations, and extending causal modeling to support larger datasets.

AI Executive Summary

Vision-language models (VLMs) rely on the interplay of a visual encoder, projection middle-layer, and decoder. However, existing methods fall short in identifying and verifying these models' behaviors. The DiaVLo framework defines expected and observed behaviors through human curation and model generation capabilities, revealing potential misalignments.

DiaVLo uses scene graph generation and human verification to construct expected behavior specifications. Models self-explain to generate observed behaviors, and causal modeling quantifies visual concept impacts. Experiments show DiaVLo's behavior labels correlate with model performance, revealing patterns in perception, organization, and prioritization.

DiaVLo provides a systematic approach for diagnosing VLM behaviors, helping identify model consistency and potential biases in multimodal tasks. This is crucial for enhancing model reliability and transparency. However, DiaVLo relies on human curation, which may introduce subjective bias. Future work could include automating the curation process and improving self-explanation accuracy.

Deep Analysis

Background

Vision-language models (VLMs) excel in multimodal tasks, combining visual encoders, projection middle-layers, and decoders. However, these models have blind spots in visual perception and task performance, leading to inconsistent behavior. Existing methods fall short in identifying and verifying VLM behaviors.

Core Problem

The problem of diagnosing VLM behaviors involves verifying that models exhibit desired output regularities while avoiding unwanted ones. This issue's importance lies in the reliable deployment and broad applicability of models.

Innovation

The DiaVLo framework combines human curation with causal modeling to provide a novel method for diagnosing VLM behaviors. Its innovation lies in defining expected and observed behaviors and quantifying the impact of visual concepts on outputs.

Methodology

  • �� Use IETrans for scene graph generation
  • �� Human verification and expansion of expected behavior specifications
  • �� Model self-explanation to generate observed behaviors
  • �� Use double machine learning to estimate causal effects

Experiments

DiaVLo is tested on four open-source VLMs and multiple datasets, including LLaVa-Bench, MMBench, SEED-Bench 2, and VQA v2. The experimental design includes analyzing the correlation between behavior labels and model performance.

Results

DiaVLo's behavior labels correlate with model performance, revealing patterns in concept perception, organization, and prioritization. The experiments show DiaVLo can provide context for model performance.

Applications

DiaVLo can be used for diagnosing VLM behaviors, helping identify model consistency and potential biases in multimodal tasks. This is crucial for enhancing model reliability and transparency.

Limitations & Outlook

DiaVLo relies on human curation, which may introduce subjective bias. The accuracy of model self-explanations needs verification. The complexity of causal modeling may limit its application on large-scale datasets.

Plain Language Accessible to non-experts

Imagine you're in a large library where librarians are responsible for categorizing books and placing them on the right shelves. DiaVLo is like a smart librarian that helps us understand how vision-language models 'read' and 'comprehend' images and text. By analyzing the model's behavior, DiaVLo can tell us if the model is categorizing information correctly and point out possible errors. Just as librarians need to ensure books are in the right place, DiaVLo helps us ensure the model's output is accurate.

ELI14 Explained like you're 14

Imagine you're playing a game that requires you to look at pictures and read text at the same time. In the game, there's an assistant that tells you how each picture and text are related. DiaVLo is like this assistant, helping us understand how complex vision-language models work. By analyzing the model's behavior, DiaVLo can tell us if the model correctly understands the relationship between pictures and text, just like the game assistant helps you win the game.

Glossary

Vision-Language Model

A model that processes both visual and language information.

Used for multimodal tasks.

Causal Modeling

A method for quantifying causal relationships between variables.

Used to quantify the impact of visual concepts on outputs.

Scene Graph Generation

The process of converting images into structured concepts and relationships.

Used to construct expected behavior specifications.

Self-Explanation

The process by which a model generates explanations for its outputs.

Used to generate observed behaviors.

Double Machine Learning

A machine learning method for estimating causal effects.

Used to quantify the impact of visual concepts on outputs.

Open Questions Unanswered questions from this research

  • 1 How to automate the human curation process to reduce subjective bias?
  • 2 How to improve the accuracy of model self-explanations?
  • 3 How to optimize causal modeling for large-scale datasets?

Applications

Immediate Applications

Model Behavior Diagnosis

DiaVLo can be used to identify consistency and potential biases in VLMs, enhancing model reliability.

Long-term Vision

Automated Curation Process

Future work could automate the curation process to reduce subjective bias, improving diagnostic efficiency and accuracy.

Abstract

Vision-language models (VLMs) rely on storing and transferring appropriate information across their sub-components. Verifying that the VLMs exhibit desired behaviours, while avoiding harmful ones, is central to their reliable deployment. Yet, methods that identify VLM behaviours remain scarce. We present DiaVLo, a diagnostic framework that leverages human curation and VLMs' generation capabilities to construct specifications of desired and observed VLM behaviours, surfacing potential misalignments. Beyond this, DiaVLo also provides causal estimates to identify the most influential concepts steering VLM behaviours. We evaluate DiaVLo on several open-source VLMs under both classification and generation conditions. Our experiments show that DiaVLo produces behaviour labels that correlate with model performance and provide context for measured performance. DiaVLo surfaced behaviours that are clearly aligned and misaligned, alongside patterns in how VLMs perceive, organise, and prioritise concepts.

cs.CL cs.AI