backward chaining


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backward chaining

[¦bak·wərd ′chān·iŋ]
(computer science)
In artificial intelligence, a method of reasoning which starts with the problem to be solved and repeatedly breaks this goal into subgoals that are more readily solvable with the relevant data and the system's rules of inference.

backward chaining

(algorithm)
An algorithm for proving a goal by recursively breaking it down into sub-goals and trying to prove these until facts are reached. Facts are goals with no sub-goals which are therefore always true. Backward training is the program execution mechanism used by most logic programming language like Prolog.

Opposite: forward chaining.

backward chaining

In AI, a form of reasoning that starts with the conclusion and works backward. The goal is broken into many subgoals or sub-subgoals which can be solved more easily. Known as top-down approach. Contrast with forward chaining.
References in periodicals archive ?
Porsteinsson and Siguroardottir (2007) used backward chaining to teach a 55-year old woman with chronic aphasia to read compound Icelandic words.
For example, if the task was to name digits but measures showed that the participant could only name the digit when it was modeled by the experimenter, then digit naming was broken down into smaller steps and taught through backward chaining.
The nonlinear transformation involved in computing successive FCM states and the process of reversing the matrix multiplication make the backward chaining difficult.
Corvid supports both data-driven forward chaining and goal-driven backward chaining, allowing the problem to be broken into small discrete parts, and making for faster structured development.
The LIFE Program uses task analyses for all tasks that detail the type of instruction (total task presentation, backward chaining, forward chaining, clustering, time delay with whole task instruction, and experiential).
For example, PROLOG employs backward chaining, CLIPS employs forward chaining, and MYCIN uses modus ponens and backward chaining Harmon, P.
If the possible results are known and if they are reasonably small in number, backward chaining is very efficient [25].
Haley is an advanced rules/inference engine with forward and backward chaining, advanced truth maintenance and integral support for higher normal forms.
Unique algorithms allow forward and backward chaining and branch swinging, so users can carry on a discussion that feels like a live conversation.