arXiv Computation and Language

See, Think, Use: Diagnosing Perception and Reasoning Failures in VLMs

The paper introduces the See, Think, Use protocol, which evaluates vision‑language models by tracing each answer back to perception, reasoning, or the use of perception. It employs two additional questions per item—a localization probe for perception and a text‑replacement probe for reasoning—without requiring model weights. The protocol measures how often answers rely on the model’s own perception across counterfactual image pairs, and demonstrates that allocating compute to the failing stage can improve performance at lower cost.

arXiv AI
Oct 21

CounterCount: Diagnosing Knowledge Bias in How Vision-Language Models Count Attributes

CounterCount is a diagnostic dataset that pairs factual and counterfactual images to test whether Vision‑Language Models (VLMs) rely on visual evidence or on world knowledge when counting attributes. Humans achieve near‑perfect accuracy on both types of images, whereas VLMs drop from 91.6% to 49.5% on counterfactuals, often defaulting to canonical counts. The study shows that VLMs exhibit a System‑1‑like bias, underutilize visual evidence, and that targeted input manipulations can mitigate this bias.

By Reem Alzahrani, Bushra Bin Hemid, Hassan Alshanqiti, Zaid Alyafeai, Paul Gavrikov, Bernard Ghanem, Abdelrahman Eldesokey
arXiv Computation and Language
Oct 22

Asking What a Director Sees Can Change What Vision-Language Models Choose

The paper investigates how asking vision‑language models to report what a director sees can alter their subsequent action choices. In a Director Task, prompting the model to identify visible blocks before selecting a block increases the likelihood of choosing a hidden block by up to 88 percentage points across several GPT models and 17 points for Qwen3.8‑27B, despite accurate reports of visible blocks. The authors argue that the question shifts the model’s perspective from the director’s to its own, and they propose a baseline paired‑prompt design for future perspective‑taking benchmarks.

By Jiaxuan Guo, Xingyu Ren, Kejia Zhang, Jingxin Yang, Youran Sun, Haizhao Yang
arXiv Machine Learning
Sep 11

New Evidence, Same Choice: Testing Physical Experiment Selection in Vision Language Models

The paper introduces a new benchmark for vision‑language models that tests their ability to decide whether to answer a physics question immediately or to request additional experimental evidence. Each problem presents one measurement image and four possible physical worlds defined by two masses and two values of another property; the model must either stop and answer or choose the cheapest experiment that resolves the question. Across six open models and 144 parameter sets, the models almost always repeat the same action even when the optimal choice changes, and only a single model gets both decisions correct on 5.9% of cases.

By Sourajit Saha, Shubhashis Roy Dipta, Nobin Sarwar, Shaswati Saha, Yuxuan Jiang, Siyuan Li, Qiheng Wang
arXiv AI
Sep 25

Reasoning Instructions Can Break Answer Decoding in Vision--Language Models

The paper shows that chain‑of‑thought (CoT) instructions can distort evaluation of vision‑language models (VLMs) when a scorer reads answer‑label logits before the model generates a rationale. On ScienceQA, Qwen2.5‑VL‑7B’s accuracy falls from 80.76% to 45.48% under this CoT‑prefix scoring, and most predictions incorrectly pick the first option. Linear probes and free generation recover most of the lost accuracy, indicating that the answer information remains in the hidden states but is missed by the early readout. The authors explain the mismatch with vocabulary and layer diagnostics, noting that probability mass shifts toward continuation tokens while answer information stays linearly accessible in later layers. The effect varies across datasets and models, but the study demonstrates that CoT‑prefix scoring can misrepresent model knowledge unless the requested and scored outputs are aligned.

By Zeyan Li, Siyuan Qiu, Jianfeng Xu
arXiv AI
Jun 2

StemBind: When MLLMs Get Lost Between Rules and Instances in Abstract Visual Reasoning

arXiv:2606. 00148v1 Announce Type: cross Abstract: Multimodal large language models (MLLMs) often know the rule but pick the wrong answer: on abstract visual reasoning (AVR) tasks, a model can describe what it sees and name the underlying pattern, yet still fail to choose the matching candidate.

By Xixiang He, Baiqi Wu, Xingming Li, Ao Cheng, Qiyao Sun, Xuanyu Ji, Qingyong Hu
arXiv AI
Jul 29

Why Does Grounding Hurt Medical VQA? Benchmarking, Diagnosis, and Fine-Tuning of Vision-Language Models

arXiv:2604. 27720v2 Announce Type: replace Abstract: Vision-language models (VLMs) are increasingly applied to medical visual question answering (Med-VQA), yet whether they can \emph{localize} the evidence behind their answers---a prerequisite for clinical auditability---is poorly characterized.

By Xupeng Chen, Binbin Shi, Chenqian Le, Qifu Yin, Lang Lin, Haowei Ni, Ran Gong, Panfeng Li