Robot Learning

Horizon (Task Horizon)

Horizon is the number of decision steps or the duration over which a task or episode unfolds, and by extension the temporal span a policy or planner must reason over. Long-horizon tasks, such as multi-stage assembly or meal preparation, compound per-step errors multiplicatively and dilute credit assignment, which is why they remain substantially harder than short-horizon skills like single grasps.

Why it matters for physical AI

Compounding error growth with horizon length is the central obstacle to reliable multi-stage autonomy, motivating hierarchical policies, subgoal decomposition, and recovery behaviors in deployed systems.