Chaining is a type of intervention that aims to create associations between behaviors in a behavior chain. A behavior chain is a sequence of behaviors that happen in a particular order where the outcome of the previous step in the chain serves as a signal to begin the next step in the chain. In terms of behavior analysis, a behavior chain is begun with a discriminative stimulus (SD) which sets the occasion for a behavior, the outcome of that behavior serves as a reinforcer for completing the previous step and as another SD to complete the next step. This sequence repeats itself until the last step in the chain is completed and a terminal reinforcer (the outcome of a behavior chain, i.e. with brushing one's teeth the terminal reinforcer is having clean teeth) is achieved. For example, the chain in brushing one's teeth starts with seeing the toothbrush, this sets the occasion to get toothpaste, which then leads to putting it on one's brush, brushing the sides and front of mouth, spitting out the toothpaste, rinsing one's mouth, and finally putting away one's toothbrush. To outline behavior chains, as done in the example, a task analysis is used.

Chaining is used to teach complex behaviors made of behavior chains that the current learner does not have in their repertoire. Various steps of the chain can be in the learner’s repertoire, but the steps the learner doesn’t know how to do have to be in the category of can’t do instead of won’t do (issue with knowing the skill not an issue of compliance). There are three different types of chaining which can be used and they are forward chaining, backward chaining, and total task chaining (not to be confused with a task analysis).