Meta-training and adaptation

Meta-RL trains across M∼p(M)M\sim p(M) to support rapid learning from limited feedback in a new task. State the task family, train/test split, visible context, and adaptation budget. Interpolation, changed dynamics, and entirely new task families are different generalization claims.

Mechanism What changes at test time Required record
Optimization-based adaptation Model parameters Gradient steps, data, initialization
Context/task inference Task representation or conditioning Available context and inference
Recurrent adaptation Hidden state Cross-episode retention and resets

The short source cites Lilian Weng and highlights memory in recurrent Meta-RL. This edition narrows that claim: an RNN is not a requirement for every meta-RL method. Parameter updates and contextual inference can also carry task information.

Exploration and control

An action can earn reward and reveal task dynamics or reward structure. Meta-training may learn both identification and control. Task IDs or privileged inputs that reveal the answer must be disclosed; otherwise fast adaptation can be overstated.

Connections and a proposed comparison

Read RL² for hidden-state adaptation, MetaVLA for demonstration conditioning, and π_RL for parameter updating. Compare zero-shot behavior, context inference, and gradient adaptation within a fixed task family while accounting for cumulative interaction. This is a proposed experiment, not a completed reproduction.

Selected references from the source notes