1. A computer-readable medium containing instructions, said instructions comprising: algorithmic instructions that define a decision tree that comprises a plurality of nodes and branches and defines a hierarchy of possible parameter configurations for a neurostimulator, wherein each node defines an alternative parameter configuration from each of the other nodes, and each branch links one of the nodes to another of the nodes; and instructions to cause a processor to: select a first parameter configuration for the neurostimulator; receive an indication of observed efficacy of the first parameter configuration; select a branch of the decision tree based on the indication of observed efficacy and a position of the first parameter configuration within the decision tree; and select a second parameter configuration for the neurostimulator based on the selected branch of the decision tree.