A method for selecting at least one action to be performed by a robotic vehicle, the method comprising: receiving as an input to a controller, including a processing system and a data storage device, signals from a plurality of sensors indicative of parameters relating to the operating environment of the robotic vehicle, the controller performing the steps of: (a) providing within the data storage device a historical database including at least one sequence of past parameters relating to the operating environment, corresponding actions taken, and corresponding scores quantifying outcomes of operation of the robotic vehicle, said historical database providing a record of a history of the controller; (b) maintaining a list of episodes, corresponding to sequences identified within the historical database, which satisfy a relevance criteria relative to a current sequence of parameters, each of said episodes being identified by a location of a time sequence within the historical database which indicates a point in the history of the controller potentially paralleling the current sequence of parameters, said relevance criteria employing a relevance function corresponding to an overall measure of similarity between the current sequence of parameters and each episode derived by combining a plurality of similarity functions; (c) performing a randomized selection between a plurality of actions, at least one of said actions being derived from an episode in said list that satisfies criteria for a measure of future expected scores for actions modeled on that episode; and (d) outputting to the robotic vehicle at least one control signal indicative of the selected action as the action to be performed, wherein, after receipt of new input signals from the plurality of sensors, the controller updates the current sequence of parameters and reevaluates said relevance criteria for each episode of said list of episodes relative to the updated current sequence of parameters; and wherein said maintaining a list of episodes comprises: (i) discarding episodes no longer satisfying said relevance criteria; and (ii) intermittently performing a search of said historical database to identify additional episodes satisfying said relevance criteria relative to the updated current sequence of parameters for inclusion in said list. (a) providing within the data storage device a historical database including at least one sequence of past parameters relating to the operating environment, corresponding actions taken, and corresponding scores quantifying outcomes of operation of the robotic vehicle, said historical database providing a record of a history of the controller; (b) maintaining a list of episodes, corresponding to sequences identified within the historical database, which satisfy a relevance criteria relative to a current sequence of parameters, each of said episodes being identified by a location of a time sequence within the historical database which indicates a point in the history of the controller potentially paralleling the current sequence of parameters, said relevance criteria employing a relevance function corresponding to an overall measure of similarity between the current sequence of parameters and each episode derived by combining a plurality of similarity functions; (c) performing a randomized selection between a plurality of actions, at least one of said actions being derived from an episode in said list that satisfies criteria for a measure of future expected scores for actions modeled on that episode; and (d) outputting to the robotic vehicle at least one control signal indicative of the selected action as the action to be performed, wherein, after receipt of new input signals from the plurality of sensors, the controller updates the current sequence of parameters and reevaluates said relevance criteria for each episode of said list of episodes relative to the updated current sequence of parameters; and wherein said maintaining a list of episodes comprises: (i) discarding episodes no longer satisfying said relevance criteria; and (ii) intermittently performing a search of said historical database to identify additional episodes satisfying said relevance criteria relative to the updated current sequence of parameters for inclusion in said list. (i) discarding episodes no longer satisfying said relevance criteria; and (ii) intermittently performing a search of said historical database to identify additional episodes satisfying said relevance criteria relative to the updated current sequence of parameters for inclusion in said list.