SoarSoarExpert System Tools Team Expert System Tools Team W09W09Daniel Nelson, Emily Schwarz, and Sean LydonDaniel Nelson, Emily Schwarz, and Sean Lydon

MotivationMotivation Soar is a unified architecture for Soar is a unified architecture for

developing intelligent systemsdeveloping intelligent systems Soar’s purpose is to be an Soar’s purpose is to be an

architecture that supports all the architecture that supports all the capabilities required of a general capabilities required of a general intelligent agentintelligent agent

First developed in 1987 at Carnegie First developed in 1987 at Carnegie MellonMellon– Now on version 9.0Now on version 9.0

FunctionalityFunctionality Represents knowledge as objects (structures with Represents knowledge as objects (structures with

multiple attributes)multiple attributes) Goal orientedGoal oriented Production rules can be stated explicitly, but are most Production rules can be stated explicitly, but are most

often broken down into often broken down into propose rulespropose rules and and operator rulesoperator rules– Propose rules state when an operator should be usedPropose rules state when an operator should be used– Operator rules perform actions (like modifying working Operator rules perform actions (like modifying working

memory)memory)– Operations can be proposed by multiple rulesOperations can be proposed by multiple rules– Eliminates duplication of the RHS of rules.Eliminates duplication of the RHS of rules.

Comes with an editor and a debuggerComes with an editor and a debugger– Both are well fleshed out with a lot of functionalityBoth are well fleshed out with a lot of functionality

Represents the working memory in a hierarchical Represents the working memory in a hierarchical manner (as a tree structure)manner (as a tree structure)

Multiple mechanisms for learningMultiple mechanisms for learning

Example of a production Example of a production rulerule

General FormatGeneral Formatsp {rule*namesp {rule*name

(condition-1)(condition-1)(condition-2)(condition-2)……(condition-n)(condition-n)-->-->(action-1)(action-1)(action-2)(action-2)……(action-n) (action-n) }}

Example of the corresponding Example of the corresponding propose and operator rulespropose and operator rules

Strengths and Strengths and WeaknessesWeaknesses StrengthsStrengths

– Can be used for production systems and Can be used for production systems and has learning functionality built inhas learning functionality built in

– Mature applicationMature application Constant developmentConstant development Committed usersCommitted users

WeaknessesWeaknesses– Lacks a simple way to interact with the Lacks a simple way to interact with the

user. No “(read)” functionuser. No “(read)” function– Lack of documentation on how to build Lack of documentation on how to build

expert systems with itexpert systems with it

Evaluation for use in CSC/CPE Evaluation for use in CSC/CPE 481481 While there is quite a bit of documentation, it While there is quite a bit of documentation, it

mostly covers more complex topics like learningmostly covers more complex topics like learning– Might be suitable for a high level general ai classMight be suitable for a high level general ai class– No resources online from other institutions that have No resources online from other institutions that have

tried teaching Soartried teaching Soar Lacks simple console based i/o and would Lacks simple console based i/o and would

therefore be unsuitable for most of our therefore be unsuitable for most of our homework assignmentshomework assignments

Steep learning curve, compounded by the lack Steep learning curve, compounded by the lack of simple examplesof simple examples

While Soar is extremely powerful, it is not While Soar is extremely powerful, it is not suitable for the purpose of teaching knowledge suitable for the purpose of teaching knowledge based systemsbased systems

ReferencesReferences Soar Manual (available with the Soar Soar Manual (available with the Soar

download, at download, at http://sitemaker.umich.edu/soar/soar_softwarhttp://sitemaker.umich.edu/soar/soar_software_downloadse_downloads) )

Soar Tutorial (Soar Tutorial (http://sitemaker.umich.edu/soar/documentatihttp://sitemaker.umich.edu/soar/documentation_and_linkson_and_links) )

A gentle Introduction to Soar: 2006 update JF A gentle Introduction to Soar: 2006 update JF Lehman, JE Laird, PS Rosenbloom, University Lehman, JE Laird, PS Rosenbloom, University of Michigan, 2006 of Michigan, 2006