The Ledger · Entry 003 · Perception
Image classification on ImageNet
Ceded to machinesSince 2015Criterion performanceLast reviewed 2026-08-17
Event
A Microsoft Research team (He, Zhang, Ren, Sun) reports 4.94 percent top-5 error on ImageNet, below the 5.1 percent measured for a trained human annotator.
The defined task is top-5 classification among one thousand object categories on a fixed benchmark; the human baseline is a single trained annotator, not a population, so the comparison is narrow. Later networks (ResNet, then vision transformers) pushed the error much lower, and the result has held. It does not carry over to open-world perception: distribution shift, adversarial patches and rare categories still trip these systems, and a fixed benchmark is not visual understanding.