| Abstract: | A simultaneous, two-choice color discrimination was carried out with three groups of four- to seven-year-old children. For Groups I and II, the opportunity to respond to the incorrect stimulus was controlled (graded) over three different conditions. First, only a red light (S+) and its retractable bar were presented (16 trials for Group I and 316 trials for Group II). Second, a green light (S−) was added with its correlated bar retracted for 14 trials. Third, 40 trials were given with both stimuli on and their correlated retractable bars extended. The opportunity to respond to S− was not graded for Group III children. They experienced only the third condition applied to Groups I and II. Responses to S+ were reinforced for all three groups, while responses to S− were not. Children in the first two groups made from zero to three responses to S−, while the control children emitted 11 to 46 errors. The results demonstrate that fading in S− or presenting S− early in the training procedure are sufficient, but not necessary conditions for errorless learning. |
