Reinforcement is the process of increasing or decreasing the weightings or parameters that gave rise to a positive or negative behaviour. The idea is based on Skinner's experiments with pigeons in the 1950s. If the mapping between stimulus, behaviour and reward is simple and direct, for example a look-up table with weights, then reinforcement is relatively straightforward. More commonly however, the causal relationship is complex and there are problems of credit assignment.
Used in glossary entries: credit assignment