information gain exploration
**Information Gain Exploration** is an **exploration strategy that rewards actions that maximize the information gained about the environment** — the agent seeks states and actions that reduce its uncertainty about the transition dynamics, reward function, or other aspects of the MDP.
**Information Gain Formulations**
- **Bayesian**: Information gain = reduction in posterior uncertainty over model parameters: $I(a; heta | s, D)$.
- **VIME**: Variational Information Maximizing Exploration — reward = KL divergence between prior and posterior dynamics.
- **Prediction Gain**: Improvement in world model prediction accuracy after experiencing a transition.
- **Empowerment**: Information gain about the relationship between actions and future states.
**Why It Matters**
- **Principled**: Information gain is a theoretically grounded exploration objective — Bayesian optimal design.
- **Efficient**: Targets exploration toward states that are most informative — avoids wasting time on irrelevant novelty.
- **Model Learning**: Naturally improves the world model — exploration and model learning are synergistic.
**Information Gain Exploration** is **seeking the most informative experiences** — exploring where uncertainty is highest to learn the environment fastest.