LINs lab releases ChronoReplay: streaming spatial VLM trained with chronological replay, achieving 63.93 OST-Bench score

ChronoReplay trains a vision-language model to answer categorical, metric, and temporal spatial questions by replaying heterogeneous supervision in chronological order.

HeyHomees Lab Notes · No. 11 · LINs lab · Published October 28, 2026

By ·

In 30 seconds

What is it?

ChronoReplay is a method that trains one vision-language model to answer categorical, metric, and temporal spatial queries by replaying heterogeneous supervision as chronologically ordered episodes, keeping each source-native target at its observation boundary.

How does it work?

The approach uses causal replay to preserve the order of trajectory turns, family-balanced learning to normalize losses across supervision families, and a single autoregressive objective for training. It fine-tunes Qwen3-VL-8B-Instruct with a frozen visual encoder while training language and merger parameters, using GPU-only ZeRO-3.

How well does it do?

Under uniform observation access (OVO-S-128), ChronoReplay scores 53.89 on OVO-S-Bench, 63.93 on OST-Bench, and 52.77 on UCS-Bench, improving over the official Qwen3-VL-8B baseline by +4.91, +13.41, and +7.44 points respectively. Adaptive access further raises OVO-S to 57.98 while using only 80.50 frames on average.

What does it need to run?

Running ChronoReplay requires the Qwen3-VL-8B-Instruct model, a GPU capable of ZeRO-3 distributed training, and the codebase from the GitHub repository, which includes scripts for environment setup, data preparation, training, and evaluation.

By the numbers

The honest read

The reported scores are self-reported by the authors on three benchmarks (OVO-S-Bench, OST-Bench, UCS-Bench) using the same causal observation access; they show relative improvements but do not provide external validation or comparison to other models. The adaptive-access gain (57.98 OVO-S with 80.50 frames) is measured on the same trained checkpoint, so it reflects inference-time changes rather than training improvements. No performance numbers are given for other hardware configurations or for the model’s behavior on real-world streaming tasks beyond the benchmark suites.

What we don't know yet

Sources

Researched and drafted with AI from the sources above; every figure is checked against them by code before it is published, and a line that fails is dropped.

More from Tech & AI →

Open HeyHomees →