RULES

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-Rhttp://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/tutoringsystem/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 feedbackhttp://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_min/lis06.mpg• http://act-r.psy.cmu.edu/papers/Lessons_Learned.html • http://www.ncrel.org/sdrs/areas/issues/content/cntareas/

reading/li1lk23.htm• http://www.audiblox2000.com/cognitiveskills.htm• http://www.britannica.com/eb/article-9053169/modus-

ponens-and-modus-tollens