Predicting future representations instead of future returns won 18 of 19 offline reinforcement learning datasets
AspireAI community · arXiv (Ni, Ni, Li, You, Du, Zhao & Jin)
Decision Transformer conditions a policy on expected future returns, which ties it to a task-specific reward function and describes the future only partially. DT-JEPA pretrains offline on reward-free trajectories to predict the distribution of future latent representations instead, using a probabilistic predictor and adaptive layer norm, then fine-tunes toward reward. On D4RL it outperformed a predictive Decision Transformer on 18 of 19 datasets, and the sensitivity analysis shows the latent predictor's capacity matters: average normalised return rose from 79.7 to 85.3 when the predictor went from one to two transformer blocks and to 87.4 at three. The theory adds a variational lower bound on the mutual information between history and future trajectories plus a finite-sample bound with an O(N^-1/4) term. The limits are that D4RL is a standard but dated benchmark family and the paper's own headline claim carries no numbers in the abstract.
Read the story and explore more from the AspireAI community.
Two sparse-autoencoder analyses have resisted scaling: matching semantically similar features across layers, and compressing large feature circuits into interpretable supernodes. This paper argues both are the same underlying problem, estimating semantic distances between SAE features that sit on different activation manifolds. Its representation treats each feature not as a single decoder vector but as an activation-weighted distribution over the hidden states expressing it, projects those distributions into a shared reference space, and compares them with Wasserstein distance. The representation is proved invariant to activation rescaling and stable under perturbation, and recovers true matches under finite-sample margin conditions. Empirically it outperformed decoder-vector and LLM-based baselines and captured subtle functional distinctions between related features, and it compressed large feature circuits into interpretable supernodes automatically. The limitation is that this is interpretability tooling: the paper demonstrates better feature matching and circuit compression, not that downstream interpretability claims become more accurate.