Concept
Errorless learning was an instructional design introduced by psychologist Charles Ferster in the 1950s as part of his studies on what would make the most effective learning environment. B. F. Skinner was also influential in developing the technique, noting that, ...errors are not necessary for learning to occur. Errors are not a function of learning or vice versa nor are they blamed on the learner. Errors are a function of poor analysis of behavior, a poorly designed shaping program, moving too fast from step to step in the program, and the lack of the prerequisite behavior necessary for success in the program. Errorless learning can also be understood at a synaptic level, using the principle of Hebbian learning ("Neurons that fire together wire together"). Many of Skinner's other students and followers continued to test the idea. In 1963, Herbert Terrace wrote a paper describing an experiment with pigeons which allows discrimination learning to occur with few or even with no responses to the negative stimulus (abbreviated S−). A negative stimulus is a stimulus associated with undesirable consequences (e.g., absence of reinforcement). In discrimination learning, an error is a response to the S−, and according to Terrace errors are not required for successful discrimination performance. A simple discrimination learning procedure is one in which a subject learns to associate one stimulus, S+ (positive stimulus), with reinforcement (e.g. food) and another, S− (negative stimulus), with extinction (e.g. absence of food). For example, a pigeon can learn to peck a red key (S+), and avoid a green key (S−). Using traditional procedures, a pigeon would be initially trained to peck a red key (S+). When the pigeon was responding consistently to the red key (S+), a green key (S−) would be introduced. At first the pigeon would also respond to the green key (S−) but gradually responses to this key would decrease, because they are not followed by food, so that they occurred only a few times or even never.