Do Vision Models Develop Human-Like Progressive Difficulty Understanding?
Zeyi Huang, Utkarsh Ojha, Yuyang Ji, Donghyun Lee, Yong Jae Lee
TL;DR
The study investigates whether vision models exhibit human-like progressive difficulty understanding by generating a synthetic, difficulty-annotated image dataset (36,000 images across 100 categories, 10 attributes, 3 difficulty levels) using GPT-4 and DALL-E 3. It introduces the Hierarchical Learning Score to quantify whether models respond to harder prompts only after mastering easier ones, and demonstrates that six popular architectures exhibit high adherence to this principle (roughly $>85%$ of triplets). A GRE-inspired adaptive testing framework is proposed to efficiently estimate overall performance using only a subset of images, achieving close alignment with full evaluation via a GRE-style score $Score = 1\cdot\text{correct}_{easy} + 2\cdot\text{correct}_{medium} + 4\cdot\text{correct}_{hard}$ and showing robust results across model types. Human-perception studies corroborate that generated difficulty correlates strongly with perceived difficulty, supporting the dataset’s validity. The work offers a practical, scalable approach to probing learning dynamics in vision models and enables faster, attribute-aware model evaluation through adaptive testing and synthetic data.
Abstract
When a human undertakes a test, their responses likely follow a pattern: if they answered an easy question $(2 \times 3)$ incorrectly, they would likely answer a more difficult one $(2 \times 3 \times 4)$ incorrectly; and if they answered a difficult question correctly, they would likely answer the easy one correctly. Anything else hints at memorization. Do current visual recognition models exhibit a similarly structured learning capacity? In this work, we consider the task of image classification and study if those models' responses follow that pattern. Since real images aren't labeled with difficulty, we first create a dataset of 100 categories, 10 attributes, and 3 difficulty levels using recent generative models: for each category (e.g., dog) and attribute (e.g., occlusion), we generate images of increasing difficulty (e.g., a dog without occlusion, a dog only partly visible). We find that most of the models do in fact behave similarly to the aforementioned pattern around 80-90% of the time. Using this property, we then explore a new way to evaluate those models. Instead of testing the model on every possible test image, we create an adaptive test akin to GRE, in which the model's performance on the current round of images determines the test images in the next round. This allows the model to skip over questions too easy/hard for itself, and helps us get its overall performance in fewer steps.
