2026-08-15 · paper-digest
Li et al.: Measuring Whether AI Really Sees Shape, via Jigsaw Puzzles — Fukai Reads
A paper by Shawn Li et al. introducing JigShape, a benchmark for spatial reasoning in vision-language models. Interlocking tab-and-blank pieces make the ground truth unique across 95,468 instances from 4x4 to 16x16; only GPT-5.5 beat chance zero-shot (69.65% on 4x4), everything collapses from 8x8 even after fine-tuning, and removing the shapes drops 97% to 10%.