Pigeons were trained to respond to stimuli from a continuous stimulus dimension (tonal frequency) with response values from continuous response dimension. Both the number of points of correspondence and problem difficulty were varied. Following training, subjects were tested with stimulus values intermediate to those trained. During these test tones, subjects emitted only those values reinforced during training. Although no intermediate responses were emitted to test tones, the average response value did vary. The study suggested that if there are fast and efficient methods to obtain control of a continuous response dimension by a continuous stimulus dimension, these methods must depend on factors other than simple generalization. (Author)