Abstract: There is disclosed a machine learning technique of determining a policy for an agent controlling an entity in a two-entity system. The method comprises assigning a prior policy and a respective rationality to each entity of the two-entity system, each assigned rationality being associated with a permitted divergence of a policy associated with the associated entity from the prior policy p assigned to that entity, and determining the policy to be followed by an agent corresponding to one entity by optimising an objective function F*(s), wherein the objective function F*(s) includes factors dependent on the respective rationalities and prior policies assigned to the two entities. In this way, the policy followed by an agent controlling an entity in a system can be determined taking into account the rationality of another entity within the system.

Abstract: There is described a machine learning system comprising a first subsystem and a second subsystem remote from the first subsystem. The first subsystem comprises an environment having multiple possible states and a decision making subsystem comprising one or more agents. Each agent is arranged to receive state information indicative of a current state of the environment and to generate an action signal dependent on the received state information and a policy associated with that agent, the action signal being operable to cause a change in a state of the environment. Each agent is further arranged to generate experience data dependent on the received state information and information conveyed by the action signal. The first subsystem includes a first network interface configured to send said experience data to the second subsystem and to receive policy data from the second subsystem.