Collect expert trajectories
Record state–action sequences from an expert policy in a known environment and standardise their format before modelling.
Recover reward functions. Assess inferred behaviour.
Inverse reinforcement learning (IRL) aims to infer a reward function that explains observed expert behaviour. Practical IRL requires recorded trajectories, a defined state–action space and an inference method; common failure cases include ambiguous rewards, partial observability and insufficient expert coverage of the state space.
Learning concept · Not a validated service
Inverse reinforcement learning (IRL) aims to infer a reward function that explains observed expert behaviour. Practical IRL requires recorded trajectories, a defined state–action space and an inference method; common failure cases include ambiguous rewards, partial observability and insufficient expert coverage of the state space.
A proposed application: infer the implicit objectives of an expert controller in a simulated robotics task to accelerate policy transfer. Any extension should keep a human in the loop for safety and validation; the supplied starter does not perform reward inference from expert trajectories.
Record state–action sequences from an expert policy in a known environment and standardise their format before modelling.
Choose an IRL formulation (e.g. maximum entropy IRL) and express the reward as a parameterised function over states or features.
Optimise the reward parameters so that the induced policy reproduces observed behaviour, and validate with held-out trajectories.
Report metrics such as likelihood of expert actions under the inferred policy, cumulative reward under the recovered reward, and inspect failure modes.
The supplied starter implements a 4-armed epsilon-greedy bandit estimator: it simulates Bernoulli rewards for four actions, updates sample-average estimates online, and reports action counts, estimated reward rates and total reward. It does not perform inverse reinforcement learning, use trajectories or infer a reward function from expert behaviour.
for step in range(1, 2001):
if rng.random() < epsilon:
action = rng.integers(len(true_reward_rates))
else:
action = int(np.argmax(estimated_values))
reward = 1 if rng.random() < true_reward_rates[action] else 0
action_counts[action] += 1
total_reward += reward
estimated_values[action] += (reward - estimated_values[action]) / action_counts[action]The code is a multi-armed bandit estimator and lacks core IRL elements: there are no environment states, no recorded expert trajectories, and no optimisation to infer a reward function from demonstrations.
A proposed extension: replace the bandit simulator with a small Gymnasium environment, collect expert trajectories, and implement a simple maximum-entropy IRL or feature-matching method to recover a reward function that explains the expert.
This is a potential application pathway, not a delivered product. The supplied starter does not implement this service or validate it with real users.
Networkers Home runs this topic inside its AI Engineer Course, with placement support and hands-on labs.