Page 45 - DCAP310_INTRODUCTION_TO_ARTIFICIAL_INTELLIGENCE_AND_EXPERT_SYSTEMS

Unit 3: Representation of Knowledge

3.2.2 Chaining Notes

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 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.

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. (e.g. 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.
3.2.3 Software Architecture

Software application architecture is the process of defining a structured solution that meets all of
the technical and operational requirements, while optimizing common quality attributes such
as performance, security, and manageability. It involves a series of decisions based on a wide
range of factors, and each of these decisions can have considerable impact on the quality,
performance, maintainability, and overall success of the application. Their definition is:
“Software architecture encompasses the set of significant decisions about the organization of a software
system including the selection of the structural elements and their interfaces by which the system is
composed; behavior as specified in collaboration among those elements; composition of these structural and
behavioral elements into larger subsystems; and an architectural style that guides this organization. Software
architecture also involves functionality, usability, resilience, performance, reuse, comprehensibility, economic
and technology constraints, trade-offs and aesthetic concerns.”
Like any other complex structure, software must be built on a solid foundation. Failing to
consider key scenarios, failing to design for common problems, or failing to appreciate the long
term consequences of key decisions can put your application at risk. Modern tools and platforms
help to simplify the task of building applications, but they do not replace the need to design
your application carefully, based on your specific scenarios and requirements. The risks exposed
by poor architecture include software that is unstable, is unable to support existing or future
business requirements, or is difficult to deploy or manage in a production environment.

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