1. A method comprising: receiving a request to evaluate a long evidential sequence task, the long evidential sequence task comprising a plurality of belief states that formulate paths, the plurality of belief states comprising a first belief state and a terminal belief state; building a search tree by executing a plurality of samples through corresponding paths until the corresponding paths are completed; identifying values for all belief states traversed during execution of the plurality of samples; and using the identified values to evaluate a reward for taking an action at any of the plurality of belief states, wherein the action is one of the following: collecting more evidence or a terminating action.