RULES
Patty Nordstrom
Hien Nguyen
"Cognitive Skills are Realized
by Production Rules"
Cognitive Skills
Cognitive skills are any mental skills that
are used in the process of acquiring
knowledge; these skills include reasoning,
perception, and intuition.
Cognitive skills refer to those skills that
make it possible for us to know.
Production Rules
• Production rules constitute a framework
for understanding human cognition
• Production rules are if-then statements or
condition-action pairs
Ex. If it snows, then I'll go skiing
Ex. If status='OK' and type=3 then count+1
Property of Rules
• Representation
• Computational
• Psychological
• Practical
Representational Power
• Represent general information about
the world
• Represent information about how to
do things in the world
• Represent linguist regularities
• Inferences such as modus ponens
Computational Power
• Problem solving
• Searching, space, heuristics
• Planning
• Sequence of rule
• Decision making
• Learning
• Acquisition, modification, application
• Language
Psychological Plausibility
• Rule-based systems can account for
different types of learning
– power law of practice
– conditioning
Practical Applicability
Learning consists of rules so how can this
be applied to helping students better
acquire rules
– Computer tutors
– Rule based cognitive systems
• ACT & ACT-R (Adaptive Control of Thought—Rational)
• SOAR (Soar is used by AI researchers to construct integrated intelligent
agents and by cognitive scientists for cognitive modeling)
Frameworks
• Frameworks – set of constructs that define
important aspects of cognition.
• Frameworks – cannot make predictions,
but you can add assumptions to make
theories
Theories
• Theories still cannot make precise
predictions
• Add assumptions about a specific situation
and it is a model of that situation
Models
• Models - theories with assumptions
about its application to a specific
situation
• Many models possible within a
theory
• Production system are theories of
human cognition
Cognitive Architectures
• Cognitive architectures are proposals
about the structure of human cognition
• Cognitive architecture tries to provide a
complete, if abstract, specification of a
system
• Production system are theories of human
cognition because they are architectures
Features of Production Systems
• Each production rule is a modular piece of
knowledge (a well-defined step of cognition)
• Complex cognitive processes:
– String a sequence of rules
– Writing to working memory (goal setting, etc)
– Reading from working memory
• Rules are condition-action asymmetrical
• Rules are abstract & apply in many situations
How do production systems
operate?
• Pattern matching
– Production’s condition vs. contents of working
memory
• Conflict resolution
• Firing a production
-> CYCLE
How to write a production system
model?
• Write a set of production rules to perform
the task
• For AI, production systems are used as
programming formalisms
– Precise, complete theories of tasks
– Without cognitive modeling
Examples
• A production system for addition
• Various production system architectures:
– PSG: first production system implemented as
a computer program
– OPS systems
• Efficient pattern matching and conflict resolution
– ACT systems: ACTE, ACT*, ACT-R
• Include a separate declarative representation
– SOAR system
ACT-R
http://act-r.psy.cmu.edu/about/
• A cognitive architecture: a theory about
how human cognition works.
• A framework
• A cognitive skill is composed of production
rules.
ACT-R: Model and Method
ACT-R: Application
ACT-R: Components
Are rules psychologically real?
• Appropriateness of rules in describing
skilled behavior
• Ability to predict the details of that
behavior
Problems
• Is ACT-R the right production system
theory?
• Assumption: production system framework
is the right way to think about cognitive
skill.
Implementation Level Problems
• Algorithm level vs. Implementation level
– High-level programming language vs.
machine level implementation
• It is difficult to identify what is going on at
the implementation level.
– Uniqueness: which implementation is the
underlying internal structure?
– Discovery: which implementation matches the
behavior?
Implementation Level Problems
• Uniqueness Problem
– Neural approach: use neural-like
computations
• Discovery Problem
– Rational approach -> ACT-R
– Cognition is adapted to environment structure:
• Memory
• Categorization
• Causal inference
• Problem solving
Intelligent Tutoring Systems
• Previously
– CAI vs. ICAI
– Impractical
• Costly
• Time
• No established paradigm for enabling students to acquire
knowledge.
• Now
– Cost reduced, advances in AI and cognitive
psychology -> shorter time, advances in cognitive
science -> instructional design implications
ITS Model
• knowledge of the
domain
• knowledge of the
learner
• knowledge of teacher
strategies
http://coe.sdsu.edu/eet/Articles/tutorin
gsystem/start.htm
What an ITS must do
• accurately diagnose students' knowledge
structures, skills, and styles
• diagnose using principles, rather than
preprogrammed responses
• decide what to do next
• adapt instruction accordingly
• provide feedback
http://coe.sdsu.edu/eet/Articles/tutoringsystem/start.htm
ACT-based approach to intelligent
tutoring
• Goal structure
• Instruction in Context
• Immediacy of Feedback
• Examples: the Geometry Tutor, the LISP
Tutor
Video: Reading Tutor
• http://www.cs.cmu.edu/~listen/videos/1998
_video_10_min/
Question?
Design Scenario
• In your group, discuss the design of an
intelligent tutoring system that teaches HTML to
highschool students. Please use the ACT-R
cognitive architecture and discuss the use of
production rules in your design.
• FOCUS:
– The degree of learner control
– Individual vs. collaborative learning
– Situated learning
– Intelligent Tutor System vs. regular Computer-Aided
Instruction
References
• http://act-r.psy.cmu.edu/about/
• http://en.wikipedia.org/wiki/ACT-R
• http://coe.sdsu.edu/eet/Articles/tutoringsystem/start.htm
• http://www.cs.cmu.edu/~listen/videos/1998_video_10_mi
n/lis06.mpg
• http://act-r.psy.cmu.edu/papers/Lessons_Learned.html
• http://www.ncrel.org/sdrs/areas/issues/content/cntareas/r
eading/li1lk23.htm
• http://www.audiblox2000.com/cognitiveskills.htm
• http://www.britannica.com/eb/article-9053169/modus-
ponens-and-modus-tollens