Chaining

Chaining is an instructional procedure used in Behavioral psychology, experimental analysis of behavior and applied behavior analysis. It involves reinforcing individual responses occurring in a sequence to form a complex behavior. It is frequently used for training behavioral sequences (or "chains") that are beyond the current repertoire of the learner. The term is often credited to the work of B.F. Skinner, an American psychologist working at Harvard University in the 1930s. Skinner based most of his work on the research done by Edward Lee Thorndike at Harvard University in the 1890s.

Procedure
The chain of responses is broken down into small steps using task analysis. Parts of a chain are referred to as links. The learner's skill level is assessed by an appropriate professional and is then either taught one step at a time while being assisted through the other steps forward or backwards or if the learner already can complete a certain percentage of the steps independently, the remaining steps are all worked on during each trial total task. A verbal stimulus or prompt is used at the beginning of the teaching trial. The stimulus change that occurs between each response becomes the reinforcer for that response as well as the prompt/stimulus for the next response without requiring assistance from the teacher. For example, in purchasing a soda you pull the money out of your pocket and see the money in your hand and then put the money in the machine. Seeing the money in your hand both was the reinforcer for the first response (getting money out of pocket) and was what prompted you to do the next response (putting money in machine).

As small chains become mastered, i.e. are performed consistently following the initial discriminative stimulus prompt, they may be used as links in larger chains. (Ex. teach hand washing, tooth brushing, and showering until mastered and then teach morning hygiene routine which includes the mastered skills). Chaining requires that the teachers present the training skill in the same order each time and is most effective when teachers are delivering the same prompts to the learner. The most common forms of chaining are backward chaining, forward chaining, and total task presentation.