Differential Reinforcement: Antecedent Control and Shaping Lecture Notes for SPEC 3020 November 17, 2009

Stimulus Control Bringing responses the learner already knows under the control of the appropriate cue or signal

Shaping Molding an existing response into the desired behavior

Setting Events Conditions and events that exist or occur at times or settings outside the environment being observed

Discriminative Stimuli Discrimination develops as a result of differential reinforcement. A certain response results in positive reinforcement (SR+) in the presence of a given stimulus or group of stimuli that are said to be discriminative stimuli (SDs) for the response. The same response is not reinforced in the presence of a second stimulus or group of stimuli, referred to as S-deltas. After a period of time, the response will occur reliably in the presence of the SD and infrequently, if at all, in the presence of the S-delta. The SD is then said to occasion the response.

Simple Discrimination A response is reinforced only in the presence of the occasioning stimulus.

Concept A class of stimuli that have characteristics in common; all members of the class occasion the same response. In order to learn a concept, a student must discriminate based on specific characteristics common to a large number of stimuli, thus forming an abstraction.

Prompts An additional stimulus that increases the probability that the SD will occasion the desired response. Offered after an SD has been presented and failed to occasion the reponse. Verbal, visual, modeling, physical guidance, Effective Prompting –Focus attention on the SD –Be as weak as possible –Fade as rapidly as possible –Avoid unplanned prompts

Verbal Prompts Rules Instructions Hints Self-operated

Visual Prompts

Modeling Characteristics that increase models’ effectiveness –Similar to themselves –Competent –Have prestige

Physical Guidance

Fading Gradual removal of prompts Errorless learning Graduated Guidance Time Delay (Good and Brophy) Increasing Assistance

Teaching Complex Behaviors Task Analysis—Breaking complex behavior into its component parts Chaining—Forming components of a task analysis –Backward chaining –Forward chaining –Total Task Presentation

Shaping Differential reinforcement of successive approximation to a specific target behavior –Terminal behavior –Initial behavior –Intermediate behaviors