RULES

Patty NordstromHien 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 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_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