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EXPERTEXPERTSYSTEMSYSTEM
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AnAn expertexpert systemsystem containscontains knowledgeknowledge
aboutabout aa particular particular fieldfield toto assistassist humanhuman
expertsexperts oror provideprovide informationinformation toto peoplepeople
whowho dodo notnot havehave accessaccess toto anan expertexpert inin
thethe particularparticular fieldfield..
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What is an Expert System ?What is an Expert System ?
AnAn expertexpert systemsystem isis defineddefined inin differentdifferent waysways::
SoftwareSoftware program program designeddesigned toto replicatereplicate thethedecisiondecision makingmaking processprocess ofof aa humanhuman expertexpert
aa program program thatthat simulatessimulates thethe judgment judgment andand
behavior behavior ofof humanhuman thatthat hashas knowledgeknowledge andand
experienceexperience inin aa particularparticular fieldfield
aa softwaresoftware thatthat givesgives computercomputer humanhuman likelike
abilitiesabilities..
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Putting all these definitions together,expertPutting all these definitions together,expert
system can be defined as :system can be defined as :
InteractiveInteractive computercomputer--basedbased systemssystems thatthat respondrespond totothethe questions,questions, asksasks forfor clarifications,clarifications, makesmakes
recommendations,recommendations, andand helpshelps thethe useruser makemake aa
betterbetter andand reasonablereasonable decisiondecision..
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ExpertExpert SystemSystem (ES)(ES) derivesderives itsits knowledgeknowledgefromfrom aa realreal livelive domaindomain expert,expert, aa humanhuman expertexpert ininparticular particular fieldfield.. AA user,user, andand expertexpert oror aaknowledgeableknowledgeable engineerengineer designsdesigns itit..
TheThe systemsystem designerdesigner interviewsinterviews andand observesobservesthethe expertexpert whowho maymay be be aa technician,technician, airbusairbusengineer,engineer, etc,etc, andand finallyfinally convertsconverts hishis wordswords andand
actionsactions andand yearsyears ofof experienceexperience intointo aa factualfactualknowledgeknowledge andand rulesrules oror simplysimply aa knowledgeknowledge basebase..
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KnowledgeKnowledge BaseBase isis aa collectioncollection ofof informationinformation
thatthat containscontains factsfacts andand aa systemsystem ofof rulesrules forfor
determiningdetermining thethe relationshiprelationship betweenbetween thosethose factsfacts..
TheThe termsterms expertexpert systemsystem andand knowledgeknowledge basebase areare
oftenoften interchangeablyinterchangeably usedused..
ExpertExpert SystemSystem goesgoes throughthrough aa numbernumber ofof
possible possible waysways andand atat lastlast comescomes upup withwith anan
acceptableacceptable solutionsolution toto thethe problemproblem..
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ItIt appliesapplies preset preset rulesrules forfor determiningdetermining thethe
problemproblem.. TheThe rulesrules cancan rangerange fromfrom 100100 toto 100100,,000000
dependingdepending onon thethe complexitycomplexity ofof thethe problemproblem..
ForFor exampleexample::
IfIf
LightLight--dodo--notnot--workwork
ThenThen
CheckCheck--thethe--batterybattery
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InIn casecase thethe batterybattery isis workingworking properlyproperly thenthenwewe cancan applyapply anotheranotherIFIF--ThenThen procedureprocedure toto havehave
thethe desireddesired resultresult
IfIf
Battery not deadBattery not dead
ThenThen
CheckCheck--thethe--connectorsconnectors
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ToTo varyingvarying degrees,degrees, expertexpert systemssystems cancanreasonreason andand makemake decisionsdecisions.. RememberRemember DeepDeep
BlueBlue aa computercomputer whichwhich defeateddefeated humanhuman chesschess
master,master, thethe systemsystem containedcontained thousandsthousands ofof
possibilitiespossibilities ofof playingplaying chesschess trickstricks..
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Expert system dialogue on skin diseaseExpert system dialogue on skin disease
diagnosis with a patientdiagnosis with a patient
ProgramProgram :: Are there any spot on the bodyAre there any spot on the body
UserUser :: YesYes
ProgramProgram :: What color spotsWhat color spots
UserUser :: Reddish brownReddish brown
ProgramProgram :: Are there more spots on theAre there more spots on the
trunk than elsewheretrunk than elsewhere
UserUser :: NoNo
ProgramProgram :: The patient has measlesThe patient has measles
This show expert system can produce bizarre output.This show expert system can produce bizarre output.
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Comparison ofHuman Expertise with ExpertComparison ofHuman Expertise with Expert
systemsystem
HumanHuman expertiseexpertise isis perishableperishable:: HumanHuman maymaychangechange jobs, jobs, theythey cancan become become ill,ill, maymay bebeinjured/deadinjured/dead andand soso onon.. ComputerComputer expertiseexpertise isispermanentpermanent..
HumanHuman expertiseexpertise isis notnot alwaysalways consistentconsistent::HumanHuman expertexpert cancan havehave offoff days,days, busybusy schedulesschedules
andand soso onon.. ComputersComputers areare alwaysalways consistent,consistent, andandgivengiven identicalidentical conditionsconditions theythey willwill alwaysalways givegivethethe samesame adviceadvice..
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HumanHuman expertiseexpertise isis difficultdifficult toto transfertransfer:: HumanHuman
beingbeing cannotcannot bebe inin twotwo placesplaces atat thethe samesame timetime..ComputerComputer expertiseexpertise isis relativerelative easyeasy toto transfertransfer..ForFor example,example, anan expertexpert systemsystem runningrunning onon aa PCPCcouldcould bebe copiedcopied toto anotheranother PCPC atat aa differentdifferent site,site,
oror downloadeddownloaded ontoonto aa networknetwork ofof PC,PC, oror evenevendownloadeddownloaded fromfrom InternetInternet..
HumanHuman expertiseexpertise isis expensiveexpensive.. EmployeeEmployeesalariessalaries areare farfar greatergreater thanthan thethe costcost ofof PCPC
hardwarehardware.. ExpertExpert system,system, eveneven takingtaking intointoaccountaccount developmentdevelopment cost,cost, areare muchmuch moremoreaffordableaffordable..
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HumanHuman areare creative,creative, oftenoften inspiredinspired;; ComputersComputersareare uninspireduninspired..
HumanHuman areare flexibleflexible;; TheyThey areare easilyeasily adaptadapt ororintegrateintegrate theirtheir expertiseexpertise withwith otherother domaindomainknowledgeknowledge;; ComputersComputers areare notnot veryvery flexibleflexible ininthisthis respectrespect..
HumanHuman posesposes commoncommon sensesense.. ExpertExpert systemsystemcannotcannot applyapply knowledgeknowledge toto aa problemproblem beyondbeyond thethedomaindomain knowledge,knowledge, andand thusthus havehave aa narrownarrow focusfocusofof thethe problemproblem..
ConsistencyConsistency:: ThereThere isis alwaysalways aa consistencyconsistency ininthethe expertexpert systemsystem.. ThereThere willwill bebe nono ambiguityambiguity ororunderstandingunderstanding problemproblem toto understandunderstand thethe expertexpertsystemsystem..
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Organizational Benefits OfExpert SystemOrganizational Benefits OfExpert System
KnowledgeKnowledge retentionretention:: TheThe knowledgeknowledge isis
permanent,permanent, unlikeunlike thatthat ofof aa humanhuman expert,expert,
whowho maymay switchswitch employment,employment, retire,retire, etcetc.. KnowledgeKnowledge distributiondistribution:: TheThe knowledgeknowledge
cancan bebe distributeddistributed withwith inin aa companycompany sitesite oror
anyany otherother sitesite anywhereanywhere inin thethe world,world, bybyusingusing networknetwork oror justjust duplicationduplication thethe expertexpert
systemsystem onon standalonestandalone hardwarehardware..
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TrainingTraining:: TheThe explanationexplanation capabilitiescapabilities ofof expertexpert
systemsystem areare suchsuch thatthat theythey oftenoften functionfunction asastrainingtraining system,system, useruser cancan seesee thethe chainchain ofof
reasoningreasoning underlyingunderlying theirtheir decisionsdecisions andand hencehence
gaingain aa better better understandingunderstanding ofof thethe problemproblem
domaindomain..
CompetitiveCompetitive edgeedge:: ExpertExpert systemsystem willwill oftenoften givegive
aa companycompany aa competitivecompetitive edge,edge, owingowing toto highlyhighly
increasedincreased responseresponse speeds,speeds, accuracyaccuracy ofof decisions,decisions,andand soso onon..
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CostCost reductionreduction:: TheThe costcost ofof providingproviding
expertiseexpertise perper useruser isis lower,lower, computerscomputers dodo notnot
paid paid largelarge salariessalaries forfor sharingsharing theirtheir
knowledge,knowledge, oror consumeconsume significantsignificant resourceresourceapartapart fromfrom energyenergy andand maintenancemaintenance costscosts..
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Advantages to the userAdvantages to the user
KnowledgeKnowledge accessibilityaccessibility:: TheThe expertiseexpertise isis
alwaysalways availableavailable onon anyany computercomputer hardwarehardware..
TrainingTraining:: TheThe valuevalue ofof trainingtraining cancan be be anan
advantageadvantage toto bothboth employeremployer andand employeeemployee..
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ConsistencyConsistency:: TheThe useruser willwill knowknow thatthat adviceadvicegivengiven isis notnot subjectsubject toto humanhuman fallibilityfallibility.. TheThe
expertexpert systemsystem isis notnot likelylikely toto havehave offoff--daysdays oror
feelfeel sicksick oror havehave tootoo manymany otherother thingsthings onon itsits
mindmind..
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BASICBASIC CONCEPTSCONCEPTS OFOF EXPERTEXPERT SYSTEMSYSTEM
AnAn expertexpert systemsystem isis aa programprogram thatthat attemptsattempts totomimicmimic humanhuman expertiseexpertise by by applyingapplying inferenceinferencemethodsmethods toto aa specificspecific bodybody ofof knowledgeknowledge..
DomainDomain :: bodybody ofof knowledgeknowledge isis callcall domaindomainDataData :: GroupGroup ofof alphabeticalphabetic symbolsymbol
a)a) 55
b)b) 66..00
c)c) 88d)d) OasisOasis
AA toto dd isis aa groupgroup ofof symbols,symbols, whichwhich havehave nono meaningmeaning onontheirtheir ownown..
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InformationInformation:: WhenWhen somesome contextcontext isis addedadded toto
thethe symbol,symbol, thatthat havehave anyany benefitbenefitisis calledcalled informationinformation..
a)a) $$55
b)b) 66..00 marksmarks awardedawarded inin thethe competitioncompetition
c)c) 88 degreedegreed)d) OasisOasis isis aa namename ofof rockrock groupgroup
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KnowledgeKnowledge:: KnowledgeKnowledge differsdiffers fromfrominformationinformation because because informationinformation
isis passivepassive inin thethe sensesense thatthat itit doesdoes
notnot givegive riserise toto furtherfurther generationsgenerations
ofof informationinformation..
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Knowledge,Knowledge, conversely,conversely, isis activeactive inin thatthat itit cancan
givegive riserise toto furtherfurther generationsgenerations ofof informationinformation..
a)a) It is raining, therefore I shall get wet!It is raining, therefore I shall get wet!
b)b) The temperature isThe temperature is 8 degree, so it is cold!8 degree, so it is cold!
c)c) The engine of the car is hot; it must have beenThe engine of the car is hot; it must have been
recently used!recently used!d)d) Oasis are affluent musicians.Oasis are affluent musicians.
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Basic Definitions :Basic Definitions :
AlgorithmsAlgorithms:: AlgorithmsAlgorithms isis aa stepstep--byby--stepstep
procedureprocedure thatthat solvessolves aa categorycategory
ofof problemsproblems.. ForForExampleExample::processing processing ofof aa companycompany payrollpayroll
useuse algorithms,algorithms, usingusing stepstep--byby--stepstep
procedureprocedure onon thethe inputinput datadata suchsuch
asas employeeemployee hours,hours, worked,worked,
overtimeovertime raterate etcetc..
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HeuristicsHeuristics:: HeuristicHeuristic solvesolve aa problemproblem byby trialtrial
andand errorerror guidedguided byby somesome
referencereference toto aa predeterminedpredetermined goalgoal..
ExampleExample:: ParkingParking system,system, RR && DD
systemsystem etcetc....
InferenceInference:: InferenceInference isis thethe drawingdrawing ofof
conclusionconclusion fromfrom premisespremises..
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SearchSearch:: TheThe processprocess ofof startingstarting inin somesome initialinitial
statestate andand attemptingattempting toto reachreach aa goalgoal statestatebyby evaluatingevaluating possiblepossible alternativealternativesolutionsolution..
Space Search:Space Search:
All of the possible states thatAll of the possible states thatcould be evaluated during acould be evaluated during asearch. The search space is oftensearch. The search space is oftenrepresented as an inverted tree,represented as an inverted tree,called a search tree.called a search tree.
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Blind search:Blind search: Blind search does not make anyBlind search does not make any
use of the knowledge about theuse of the knowledge about the
problem to guide the search.problem to guide the search.
Heuristic search:Heuristic search: Heuristic search use domainHeuristic search use domain--specific knowledge to traverse thespecific knowledge to traverse the
search spacesearch space
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COMPONENTSOF ANEXPERTSYSTEMCOMPONENTSOF ANEXPERTSYSTEM
a). Knowledge Basea). Knowledge Base
TheThe componentscomponents ofof expertexpert systemsystem thatthat containscontainsthethe systems systems knowledgeknowledge isis calledcalled knowledgeknowledge
basebase systemsystem..
ThisThis knowledgeknowledge isis frequentlyfrequently representedrepresented inin aacomputercomputer inin thethe form form ofof rulesrules:: theythey storestore thethe
heuristicheuristic thatthat guideguide thethe humanhuman expertexpert..
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Example : A typical rule used by a house mortgageExample : A typical rule used by a house mortgage
expert might be:expert might be:IF the applicant likes the houseIF the applicant likes the house
AND the house is worth a surveyAND the house is worth a survey
THEN advise the applicant to apply for a loanTHEN advise the applicant to apply for a loan
Rule would usually be expressed in the formRule would usually be expressed in the form
IF condition (s)IF condition (s)
THEN actions (s)THEN actions (s)
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TheThe actionaction (s)(s) areare executedexecuted whenwhen thethe conditioncondition
(s)(s) ofof thethe rulerule areare satisfiedsatisfied.. TheThe rulesrules createdcreated inin
thisthis wayway areare collectivelycollectively calledcalled thethe knowledgeknowledgebase/base/ rulerule basedbased systemsystem..
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b).b). InferenceInference
Inference is the drawing of conclusion fromInference is the drawing of conclusion from
premises.premises.
Various forms of inferenceVarious forms of inference::
DeduDeductive and Inductivective and Inductive inference being two of theinference being two of themost commonly used.most commonly used.
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Deductive inferenceDeductive inference
ExampleExample::
SalmanSalman isis aa programmer programmer ((11))
AllAll programmersprogrammers areare happyhappy ((22))ThereforeTherefore SulmanSulman isis happyhappy ((33))
TheThe conclusionconclusion ((33)) inin thisthis exampleexample isis aalogicallogical consequenceconsequence ofof oror cancan bebe deduceddeduced fromfromthethe premises premises ((11)) andand ((22))..
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InIn thisthis example,example, thethe conclusionconclusion cancan bebeinferredinferred solelysolely fromfrom thethe informationinformation givengiven.. ThisThis
deductiondeduction isis aa consequenceconsequence ofof entailmententailment thatthat
leadsleads toto aa formform ofof reasoningreasoning thatthat isis
mathematicallymathematically exactexact.. ThisThis meansmeans thatthat ifif thethepremises premises areare truetrue thethe conclusionconclusion isis guaranteedguaranteed
alsoalso toto bebe truetrue..
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Inductive inferenceInductive inference
ExampleExample::
AllAll animalsanimals eateat ((44))
ThereforeTherefore allall kangarooskangaroos eateat ((55))
OnOn firstfirst inspection,inspection, itit mightmight bebe temptingtempting totoassumeassume thatthat thethe aboveabove conclusionconclusion ((55),), namelynamely allall
kangarooskangaroos eat,eat, followsfollows by by deductiondeduction fromfrom thethepremisepremise ((44)).. HoweverHowever thisthis assumptionassumption isis falsefalse forforthethe premisepremise givengiven sayssays nothingnothing aboutabout whetherwhether orornotnot aa kangarookangaroo isis anan animalanimal..
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Hence,Hence, thethe conclusionconclusion ((55)) doesdoes notnot havehave thethesamesame mathematicalmathematical exactnessexactness thatthat thethe previousprevious
conclusionconclusion ((33)) hadhad.. ForFor thethe conclusionconclusion ((55)) toto bebe
truetrue wewe wouldwould havehave toto induceinduce thethe assumptionassumption
thatthat anan animalanimal isis aa kangarookangaroo toto thethe givengivenpremisepremise ((44)) fromfrom thethe commoncommon--sensesense knowledgeknowledge
ofof thethe worldworld.. ForFor thisthis reason,reason, suchsuch inferencesinferences areare
calledcalled inductiveinductive inferencesinferences..
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Declarative Knowledge:Declarative Knowledge:
Example:Example:
Aslam likes tennisAslam likes tennis (6)(6)
Everything that Aslam likes, Saleem likesEverything that Aslam likes, Saleem likes (7)(7)
DeductiveDeductive reasoningreasoning leadsleads toto thethe conclusionconclusion
thatthat SaleemSaleem likeslikes tennistennis givengiven thethe aboveabove premisespremises..TheThe rulerule ((77)) andand factfact ((66)) thatthat areare givengiven leadlead toto thisthis
conclusionconclusion..
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TheThe conclusionconclusion isis foundfound by by reasoningreasoning withwith
whatwhat isis given,given, notnot byby explicitlyexplicitly programmingprogramming thethe
computercomputer onon howhow toto reachreach thethe solutionsolution..
AnAn exampleexample ofof aa languagelanguage thatthat usesuses thethedeclarativedeclarative paradigm paradigm isis thethe AIAI languagelanguage
PROLOGPROLOG (programming(programming logic)logic);; itit containscontains anan inin--
builtbuilt logiclogic toto deducededuce solutionsolution toto thethe problemsproblems ofof
thethe declarativedeclarative typetype..
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Procedure knowledgeProcedure knowledge
ConventionalConventional algorithmicalgorithmic paradigm paradigm thatthat
describesdescribes howhow aa procedureprocedure isis executedexecuted bybyexplicitlyexplicitly describingdescribing thethe stepssteps involvedinvolved reachingreaching aa
solutionsolution..
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Inference engineInference engine
HumanHuman expertexpert whowho havehave toto knowknow notnot onlyonly
whichwhich rulesrules toto apply,apply, butbut alsoalso inin whatwhat orderorder theythey
shouldshould be be appliedapplied toto solvesolve aa particular particular problemproblem..SimilarlySimilarly anan expertexpert systemsystem needneed toto decidedecide whichwhich
rules,rules, andand inin whatwhat order,order, shouldshould be be selectedselected forfor
evaluationevaluation.. ToTo thisthis anan expertexpert systemsystem usesuses anan
inferenceinference engineengine..
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OrOr inin otherother wordswords
InferenceInference engineengine isis aa programprogram thatthat interpretsinterprets thethe
rulesrules inin thethe knowledgeknowledge base base inin orderorder toto drawdraw
conclusionsconclusions..
OrOr inin otherother wordswords
InferenceInference engine,engine, aa componentcomponent ofof expertexpert systemsystem
controlscontrols howhow andand whenwhen thethe informationinformation inin thetheknowledgeknowledge basebase isis appliedapplied
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TwoTwo mainmain alternativealternative strategiesstrategies areare useuse withwith
ruleruleb
asedb
ased systemsystem
a)a) BackwardBackward--chainingchaining InferenceInference EngineEngine
ThisThis isis aa goalgoal orientedoriented inin thethe sensesense thatthat itit triestries
toto proveprove aa goalgoal oror rulerule
conclusionconclusion byby confirmingconfirming thethe truthtruth ofof allall ofof itsitspremisespremises..
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IFIF thethe stainstain ofof thethe organismorganism isis gramgramnegativenegative
ANDAND thethe morphologymorphology ofof thethe organismorganism isis rodrod
ANDAND thethe aerobicityaerobicity ofof thethe organismorganism isisanaerobicanaerobic
THENTHE N therethere isis stronglystrongly suggestivesuggestive evidenceevidencethatthat thethe classclass ofof thethe organismorganism isis
EnterobacteriaceaeEnterobacteriaceae
InIn thisthis example,example, thethe inferenceinference engineengine triestries totoproveprove thethe conclusionconclusion ofof thethe rulerule byby attemptingattempting totoproveprove eacheach premisepremise leadingleading toto thethe rulerule conclusionconclusion..
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b)b) ForwardForward--ChainingChaining InferenceInference EngineEngine..
ItIt examinesexamines thethe currentcurrent statestate ofof thethe knowledgeknowledge
basebase andand finds finds thosethose rulesrules thatthat whosewhose premisespremisescancan bebe satisfiedsatisfied fromfrom knownknown givengiven datadata andand addsadds
thethe conclusionsconclusions ofof thosethose rulesrules toto thethe knowledgeknowledge
basebase
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forfor examplesexamples ::
IfIf MalariaMalaria isis diagnosed,diagnosed, teststests etcetc.. maymay bebe
requestedrequested forfor confirmationconfirmation..
ThiefThief couldcould be be prosecuted prosecuted inin thethe thefttheft casecase
throughthrough CourtCourt hearingshearings andand trialstrials etcetc..
UserUser InterfaceInterface
TheThe componentcomponent ofof anan expertexpert system system thatthatcommunicatescommunicates withwith thethe useruser isis knownknown asas useruser
interfaceinterface..
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AnAn expertexpert systemsystem useruser interfaceinterface isis normallynormally ofof
aa highlyhighly interactiveinteractive nature,nature, toto reflectreflect thethe formform ofof
dialoguedialogue thatthat taketake placeplace betweenbetween aa clientclient andand aa
humanhuman expertexpert..
UserUser interfaceinterface willwill notnot onlyonly enableenable thethe useruser totoansweranswer questionsquestions but but alsoalso allowallow thethe useruser toto
interruptinterrupt itsits runningrunning operationoperation by by askingasking forfor
explanationsexplanations..
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ForFor example,example, aa useruser ofof aa medicalmedical expertexpertsystemsystem mightmight wantwant toto knowknow whywhy systemsystem asksasks forfor
thethe patientspatients ageage.. ThisThis typetype ofof interrogativeinterrogative isiscalledcalled aa WhyWhy explanationexplanation..
AnotherAnother typetype ofof explanationexplanation interrogativeinterrogative isis
thethe HowHow questionquestion.. ThisThis isis normallynormally usedused totoquestionquestion howhow thethe systemsystem arrivedarrived atat aa particularparticulardecisiondecision..
For For example,example, ifif aa useruser ofof aa medicalmedical expertexpertsystemsystem isis toldtold thatthat thethe patientpatient hashas meningitis,meningitis, thetheuseruser mightmight wantwant toto knowknow howhow thethe systemsystem arrivedarrivedatat thisthis conclusionconclusion..
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Architecture OfAn Expert SystemArchitecture OfAn Expert System
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DECISIONSUPPORTSYSTEMDECISIONSUPPORTSYSTEM
DecisionDecision supportsupport systemssystems (DSS)(DSS) areare aa branch branch ofofOperationalOperational ResearchResearch (OR),(OR), whichwhich evolvedevolved fromfrom thetheneedneed toto applyapply quantitativequantitative techniquestechniques toto thethe solutionsolutionofof complexcomplex managementmanagement problemsproblems..
DSSDSS areare traditionallytraditionally definedefine asas thethe applicationapplication ofof
OperationalOperational ResearchResearch..
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DECISION SUPPORT SYSTEM and EXPERTDECISION SUPPORT SYSTEM and EXPERT
SYSTEMSYSTEM
DSSDSS supportsupport decisiondecision makersmakers usingusing datadata processingprocessingand/orand/or OROR techniquestechniques;; ExpertExpert systemsystem makemake thethedecisiondecision themselvesthemselves..
ExpertExpert systemssystems areare notnot appliedapplied toto problemsproblems requiringrequiringthethe mathematicalmathematical optimizationoptimization techniquestechniques thatthat areare
appliedapplied toto traditionaltraditional DSSDSS..
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ExpertExpert systemssystems cancan bebe appliedapplied toto problemsproblems whosewhoseobjectivesobjectives andand constraintsconstraints areare difficultdifficult toto specifyspecify ininquantityquantity termsterms..
ExpertExpert systemssystems areare effectiveeffective forfor elicitingeliciting alternativesalternatives
asas part part ofof thethe solutionsolution processprocess;;
thesethese maymay includeincludewhatwhat ifif scenariosscenarios etcetc.. ThisThis isis duedue toto thethe reasoningreasoningcapabilitiescapabilities ofof expertexpert systemssystems..
DSSDSS oftenoften aidaid humanhuman decisiondecision makingmaking by by somesomequalitativequalitative oror quantitiesquantities analysis,analysis, whereaswhereas expertexpertsystemsystem trytry toto replacereplace thethe humanhuman expertiseexpertise oror expertexpert..
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Decision Support System Verses Expert SystemDecision Support System Verses Expert System
AttributesAttributes DSSDSS Expert systemExpert system
ObjectivesObjectives
Major orientationMajor orientation
Decision makerDecision maker
Problem domainProblem domain
World viewWorld view
Query directionQuery direction
Data manipulationData manipulation
Mathematical modelsMathematical models
IncorporatedIncorporated
Assist decision makingAssist decision making
Decision makingDecision making
User and/or systemUser and/or system
Broad, complexBroad, complex
OpenOpen
Human queriesHuman queries
Numerical/symbolicNumerical/symbolic
--
Copy and replaceCopy and replace
Human CapabilitiesHuman Capabilities
Transfer of experienceTransfer of experience
SystemSystem
NarrowNarrow
ClosedClosedSystem queries humanSystem queries human
SymbolicSymbolic
--
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EXPERTSYSTEMIN BUSSINESSESEXPERTSYSTEMIN BUSSINESSES
SupposeSuppose youyou ownown aa realreal estateestate business,business,andand youyou generategenerate overover 4040 percent percent ofof youryourrevenuerevenue fromfrom appraisingappraising commercialcommercial realreal
estateestate.. ConsiderConsider furtherfurther thatthat onlyonly oneone personperson ininyouryour firmfirm isis capablecapable ofof performing performing thesetheseappraisalsappraisals.. WhatWhat ifif thatthat personperson werewere toto quitquit ??HowHow dodo youyou replacereplace thatthat expertise?expertise? HowHow fastfast
cancan youyou findfind someonesomeone elseelse ?? HowHow muchmuchbusinessbusiness wouldwould youyou loselose ifif itit tooktook youyou aa monthmonthtoto findfind aa suitablesuitable replacementreplacement ??
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InIn business, business, peoplepeople areare valuablevaluable becausebecause theythey
performperform importantimportant businessbusiness taskstasks.. ManyMany ofof thesethesebusiness business taskstasks requirerequire expertise,expertise, andand peoplepeople oftenoften
carrycarry expertiseexpertise inin theirtheir headsheads andand thatsthats thethe onlyonly
placeplace itit cancan bebe foundfound inin thethe organizationorganization.. AIAI cancan
provideprovide youyou withwith anan expertexpert systemsystem thatthat cancan capturecaptureexpertise,expertise, thusthus makingmaking itit availableavailable toto thosethose whowho areare
expertsexperts soso thatthat theythey cancan useuse it,it, eithereither toto solvesolve aa
problemproblem oror toto learnlearn howhow toto solvesolve aa problemproblem..
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APPLICATIONSOFEXPERTSYSTEMAPPLICATIONSOFEXPERTSYSTEM
AnAn expertexpert systemsystem isis usuallyusually builtbuilt forfor aa specificspecific
applicationapplication areaarea calledcalled aa domaindomain.. YouYou cancan findfind expertexpert
systemssystems inin thethe followingfollowing domainsdomains::
AccountingAccounting for for auditing,auditing, taxtax planning,planning,
managementmanagement consultingconsulting andand TrainingTraining etcetc..
MedicineMedicine toto prescribe prescribe antibioticsantibiotics wherewhere manymanyconsiderationsconsiderations mustmust bebe takentaken intointo accountaccount (such(such asas
thethe patientspatients medicalmedical history,history, thethe sourcesource ofof infection,infection,
thethe mostmost inexpensiveinexpensive drugdrug available)available)
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ProcessProcess controlcontrol forfor example,example, toto controlcontrol offsetoffset
lithographiclithographic printingprinting HumanHuman ResourceResource ManagementManagement toto helphelp personnelpersonnel
managersmanagers determinedetermine whetherwhether theythey areare inin
compliancecompliance withwith anan arrayarray ofof federalfederal employmentemployment
lawslaws..
FinancialFinancial ManagementManagement -- toto identifyidentify delinquencydelinquency--
proneprone accountsaccounts inin thethe loanloan departmentsdepartments ofof banksbanks..
ProductionProduction -- toto guideguide thethe manufacturemanufacture ofof allall sortssorts ofofproducts,products, suchsuch asas aircraftaircraft parts,parts, andand soso onon
ForestryForestry ManagementManagement -- toto helphelp withwith harvestingharvesting
timbertimber onon forestforest landslands
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Expert System to Control Traffic LightExpert System to Control Traffic Light
LetsLets looklook atat aa veryvery simplesimple expertexpert systemsystem thatthat
wouldwould telltell aa driverdriver whatwhat toto dodo whenwhen approachingapproaching aa
traffictraffic lightlight.. DealingDealing withwith traffictraffic lightlight isis thethe typetype ofofproblemproblem toto whichwhich anan expertexpert systemsystem isis wellwell -- suitedsuited..
ItIt isis aa recurringrecurring problem,problem, andand toto solvesolve itit youyou followfollow
aa wellwell--defineddefined setset ofof stepssteps.. YouYou havehave probablyprobably gonegone
throughthrough thethe followingfollowing mentalmental questionquestion andand answeranswersessionsession many,many, manymany timestimes withoutwithout eveneven realizingrealizing itit..
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WhenWhen youyou approachapproach aa greengreen traffictraffic light,light, youyouproceedproceed onon throughthrough.. IfIf thethe lightlight isis red,red, youyou trytry toto stopstop..
IfIf youyou areare unableunable toto stop,stop, andand ifif traffictraffic isis approachingapproaching
fromfrom thethe leftleft oror right,right, youyou willwill probablyprobably byby inin troubletrouble..
Similarly,Similarly, ifif thethe lightlight isis yellow,yellow, youyou maymay bebe ableable totomakemake itit throughthrough thethe intersectionintersection beforebefore thethe lightlight turnsturns
redred.. IfIf not,not, youyou willwill againagain bebe facedfaced withwith problemproblem ofof
approachingapproaching traffictraffic..
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Expert System to Control Traffic LightExpert System to Control Traffic Light
RuleSymptomRuleSymptomorFactorFact
YesYes NoNo ExplanationExplanation
1). Is the light1). Is the light
green?green?
Go through theGo through the
Intersection.Intersection.
Go to Rule2.Go to Rule2. ShouldShould be be safesafe ifif
lightlight isis GreenGreen ..IfIf
not,not, needneed moremore
informationinformation..
2). Is the light2). Is the light
red?red?
Go to Rule 4Go to Rule 4 Go to Rule 3Go to Rule 3 Should stop, mayShould stop, may
not be able to.not be able to.
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33)).. IsIs thethe lightlight
likelylikely toto ChangeChange
toto redred beforebefore
youyou getget throughthrough
thethe Intersection?Intersection?
Go to Rule 4Go to Rule 4 GoGo throughthrough thethe
intersectionintersection
WillWill onlyonly reachreach
thisthis pointpoint ifif lightlight
isis yellow,yellow, thenthenyouyou willwill havehave
twotwo choiceschoices..
44)).. CanCan youyou stopstop
before before enteringenteringthethe intersection?intersection?
StopStop Go to Rule 5Go to Rule 5 ShouldShould stop,stop, butbut
therethere maymay be be aaproblem problem ifif youyou
cantcant stopstop..
55)).. IsIs traffictraffic
approachingapproachingfromfrom eithereither sideside
PreparePrepare toto crashcrash GoGo throughthrough thethe
IntersectionIntersection
UnlessUnless thethe
intersectionintersection isisclearclear ofof traffictraffic
youyou areare likelylikely toto
crashcrash
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WHATEXPERTSYSTEMSCAN DOWHATEXPERTSYSTEMSCAN DO
AnAn expertexpert systemsystem usesuses ITIT toto capturecapture andand applyapplyhumanhuman expertiseexpertise.. ForFor problemsproblems withwith clearclear rulesrules andand
procedures,procedures, expertexpert systemssystems workwork veryvery wellwell andand cancanprovide provide youryour companycompany withwith greatgreat advantagesadvantages.. AnAnexpertexpert systemsystem cancan::
HandleHandle massivemassive amountsamounts ofof informationinformation
ReduceReduce errorserrors
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AggregateAggregate informationinformation fromfrom variousvarious sourcessources
ImproveImprove customercustomer serviceservice
ProvideProvide consistencyconsistency inin decisiondecision makingmaking
ProvideProvide newnew informationinformation
DecreaseDecrease personnelpersonnel timetime spentspent onon taskstasks
ReduceReduce costcost
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WhereExpert Systems AreMost EffectiveWhereExpert Systems AreMost Effective
ExsysExsys IncInc.. developsdevelops andand implementsimplements advisoryadvisorysystemsystem whichwhich areare distributeddistributed viavia thethe Internet,Internet,
IntranetsIntranets oror throughthrough standstand--alonealone technologytechnology.. PotentialPotentialcustomers,customers, supportsupport staff,staff, clientsclients andand employeesemployees areareableable toto interactinteract withwith thesethese systemssystems toto obtainobtainrecommendations,recommendations, asas ifif theythey werewere consultingconsulting withwith aafirms'firms' BestBest ExpertsExperts -- andand they'rethey're availableavailable 2424 hourshours aa
dayday..
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Exsys'sExsys's approachapproach andand techniquestechniques ofofknowledgeknowledge codificationcodification andand representationrepresentation havehave
beenbeen highlyhighly successfulsuccessful overover thethe lastlast 1717 yearsyears withwith
thousandsthousands ofof advisoryadvisory systemssystems inin useuse worldwideworldwide..
AsAs partpart ofof thethe preliminarypreliminary processprocess ofof workingworkingwithwith youryour firm,firm, ExsysExsys firstfirst identifiesidentifies thethe
appropriateappropriate projectproject areasareas thatthat willwill benefitbenefit mostmost byby
implementingimplementing advisoryadvisory systemssystems..
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ToTo getget thethe bestbest useuse ofof expertexpert knowledgeknowledge inin advisoryadvisorysystems,systems, thethe problemproblem--solvingsolving logiclogic shouldshould::
.... BeBe wellwell understoodunderstood andand documenteddocumented
.... BeBe basedbased onon logicallogical steps/procedures/businesssteps/procedures/business rulesrules
.... Not Not involveinvolve intuition,intuition, guesses,guesses, oror be be based based ononarbitraryarbitrary "personal"personal taste"taste" decisionsdecisions
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RegulatoryComplianceRegulatoryCompliance
ThoughThough thethe knowledgeknowledge inin thisthis areaarea cancan bebe veryverycomplex,complex, regulationsregulations areare generallygenerally documenteddocumented inin aaformform veryvery similarsimilar toto thethe IF/THENIF/THEN formform ofof businessbusinessrulesrules.. RegulatoryRegulatory systemssystems insureinsure thatthat allall possiblepossible
relevantrelevant regulationsregulations areare consideredconsidered andand allall policiespoliciesfollowedfollowed consistentlyconsistently.. TheseThese systemssystems provideprovidesignificantsignificant costcost savingssavings byby helpinghelping companiescompanies staystaywithinwithin industryindustry compliance,compliance, protectprotect employees,employees, avoidavoidpotential potential fines,fines, andand possiblepossible badbad publicitypublicity.. WhetherWhether
onlineonline oror runrun asas aa download,download, compliancecompliance advisoryadvisorysystemssystems provideprovide aa moremore personalizedpersonalized andand confidentialconfidentialenvironmentenvironment andand interfaceinterface..
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Product Selection /Product Selection / RecommendationRecommendation
SelectingSelecting whichwhich productsproducts bestbest meetmeet aa customerscustomersneedsneeds andand requirementsrequirements cancan be be aa veryvery intricateintricateprocessprocess.. ButBut itit isis oneone thatthat cancan bebe expressedexpressed inin logiclogic
rulesrules relatingrelating toto customercustomer needsneeds andand productproductspecificationsspecifications.. UnlikeUnlike casecase--based based oror "learning""learning"approaches,approaches, expertexpert systemssystems handlehandle conflictingconflictingrequirementsrequirements andand alwaysalways givegive aa recommendationrecommendation ofof
thethe bestbest fit,fit, eveneven whenwhen allall customercustomer desiresdesires cancan notnot bebemetmet.. AdvisoryAdvisory systemssystems alsoalso makemake itit possiblepossible forfor staffstafftoto identifyidentify crosscross--sellingselling opportunitiesopportunities andand bebe ableable totosellsell aa muchmuch broader,broader, moremore complexcomplex productproduct lineline..
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ConfigurationConfiguration
ConfiguringConfiguring complexcomplex systemssystems withwith manymany piecespiecesisis veryvery complexcomplex.. DeterminingDetermining whichwhich pieces pieces arearerequiredrequired andand whichwhich areare incompatibleincompatible requiresrequires detaileddetailed
knowledgeknowledge andand analysisanalysis.. ThisThis isis anan idealideal problemproblem forforanan expertexpert system,system, whichwhich cancan guaranteeguarantee validvalid andandcompletecomplete configurationsconfigurations.. TheThe systemsystem cancan alsoalso explainexplainthethe reasonreason forfor itsits recommendationrecommendation.. DifferentDifferent aspectsaspectscancan comecome intointo playplay atat thethe samesame time,time, forfor instanceinstance::
inventory,inventory, currentcurrent pricingpricing andand customercustomer requirementsrequirements..TheThe expertexpert systemsystem alsoalso enablesenables comparisoncomparison ofof "what"whatif"if" scenariosscenarios..
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ProblemProblem--Solving DiagnosticsSolving Diagnostics
WhenWhen expertsexperts identifyidentify malfunctionsmalfunctions oror interpretinterpretcomplexcomplex data,data, theythey quicklyquickly looklook forfor symptomssymptoms indicativeindicative ofofparticularparticular problemsproblems.. TheThe knowledgeknowledge ofof howhow toto handlehandle thesetheseproblemsproblems isis idealideal forfor conversionconversion intointo anan advisoryadvisory systemsystem..
ThereThere areare usuallyusually manymany domaindomain expertsexperts throughoutthroughout aabusinessbusiness enterpriseenterprise.. TheyThey areare oftenoften repeatedlyrepeatedly interruptedinterrupted totoansweranswer commoncommon questionsquestions byby thosethose withwith lessless expertiseexpertise..AdvisoryAdvisory systemssystems freefree upup expertsexperts toto handlehandle moremore complexcomplexproblemsproblems andand projects projects byby makingmaking thisthis knowledgeknowledge accessibleaccessible
byby employeesemployees oror customerscustomers thatthat needneed itit.. TheseThese systemssystems arearealsoalso beneficialbeneficial inin capturingcapturing andand codifyingcodifying thethe problemproblem --solvingsolving expertiseexpertise ofof thesethese bestbest peoplepeople thatthat maymay bebe retiringretiring ororchangingchanging jobsjobs..
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Data AnalysisData Analysis
ThereThere areare manymany typestypes ofof datadata analysisanalysis whichwhich requirerequire
bothboth numericnumeric analysisanalysis andand complexcomplex logiclogic analysisanalysis ofof thethe
datadata.. ExpertExpert systemssystems areare anan idealideal wayway toto dealdeal withwith suchsuch
problemsproblems.. TheThe purely purely numericnumeric analysisanalysis cancan be be handledhandled
internally,internally, oror itit cancan bebe interfacedinterfaced toto otherother externalexternal programsprograms..
TheThe additionaddition ofof powerfulpowerful rulerule--basedbased logiclogic analysisanalysis makesmakes itit
possible possible toto handlehandle veryvery complexcomplex problems problems thatthat werewere
previouslypreviously impracticalimpractical.. PersonsPersons interactinginteracting withwith thethe systemssystems
thenthen don'tdon't requirerequire thethe extensiveextensive knowledgeknowledge ofof interpretinginterpretingdatadata.. TheThe expertexpert systemsystem analysisanalysis process process cancan alsoalso bebe
completelycompletely embeddedembedded withinwithin otherother systemssystems toto appearappear
invisibleinvisible toto endend--useruser..
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Customer/Product SupportCustomer/Product Support
TheseThese problemsproblems areare inin mostmost waysways similarsimilar toto diagnosticdiagnosticproblems, problems, but but oftenoften gogo beyond beyond thethe diagnosisdiagnosis ofof aamalfunctionmalfunction andand includeinclude followingfollowing aa precise precise sequencesequence ororspecificspecific policypolicy andand proceduresprocedures.. ManyMany otherother typestypes ofof "help"help
desk"desk" softwaresoftware givegive aa guessguess atat aa possible possible solutionsolution -- thetheexpertexpert systemsystem approachapproach willwill consistentlyconsistently givegive thethe bestbestrecommendationrecommendation.. .. TheyThey onlyonly askask pertinent pertinent questionsquestionsinsteadinstead ofof forcingforcing aa customercustomer toto gogo throughthrough aa longlong listlist ofofQ&AQ&A toto comecome upup withwith aa solutionsolution.. AdvisoryAdvisory systemssystems withinwithinhelphelp desksdesks helphelp bring bring lessless experiencedexperienced staffstaff upup toto speedspeed
quicklyquickly withoutwithout repeatedrepeated trainingtraining oror interruptionsinterruptions.. OnlineOnlinecustomercustomer helphelp systemssystems provide provide aa moremore personalizedpersonalizedenvironmentenvironment andand interface,interface, andand theirtheir automationautomation helpshelps freefreeadvisorsadvisors toto provideprovide valuevalue--addedadded "emotional""emotional" supportsupport..
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Background MonitoringBackground Monitoring
InIn additionaddition toto beingbeing interactive,interactive, expertexpert systemssystems logicallogical
processingprocessing powerpower cancan bebe runrun inin thethe backgroundbackground toto monitormonitor
datadata streamsstreams.. TheyThey cancan be be constantlyconstantly analyzinganalyzing thethe datadata
streamsstreams (often(often realreal--time)time) forfor developingdeveloping problems,problems, specialspecial
opportunities,opportunities, oror otherother informationinformation thatthat shouldshould bebe
immediatelyimmediately brought brought toto someone'ssomeone's attentionattention.. TheyThey areare
especiallyespecially usefuluseful forfor identifyingidentifying veryvery uncommonuncommon problemsproblems
thatthat fewfew knowknow howhow toto solve,solve, andand cancan preventprevent whatwhat couldcould bebe
catastrophiccatastrophic resultsresults.. TheseThese systemssystems cancan alsoalso alertalert anotheranothersystemsystem toto veryvery rarerare situationssituations thatthat normallynormally wouldwould bebe tootoo
monotonousmonotonous oror expensiveexpensive toto monitormonitor..
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Inconsistency DetectionInconsistency Detection
ExpertExpert systemssystems cancan checkcheck customercustomer datadata againstagainst
policiespolicies andand proceduresprocedures toto detectdetect inconsistenciesinconsistencies thatthat
maymay indicateindicate problems problems likelike fraudfraud oror otherotherirregularitiesirregularities.. TheThe abilityability ofof thethe expertexpert systemssystems toto
handlehandle complexcomplex logiclogic allowsallows suchsuch systemssystems toto bebe muchmuch
"smarter","smarter", both both inin detectiondetection andand inin recognitionrecognition ofof
illegitimateillegitimate usersusers thatthat mightmight triggertrigger otherother systemssystems..
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Smart QuestionnairesSmart Questionnaires
OneOne ofof commoncommon usesuses ofof expertexpert systemssystems isis totomakemake questionnairesquestionnaires moremore intelligentintelligent.. TheThe logiclogic ofof ananexpertexpert systemsystem leadsleads toto askingasking onlyonly pertinentpertinentquestionsquestions thatthat havehave beenbeen determineddetermined toto bebe relevant,relevant,duedue toto answersanswers alreadyalready providedprovided.. AllAll relevantrelevantquestionsquestions areare asked,asked, andand nono irrelevantirrelevant questionsquestions areareaskedasked.. ThisThis producesproduces aa farfar superiorsuperior useruser interfaceinterface.. InIn
addition,addition, thethe datadata cancan be be analyzedanalyzed asas itit isis bebecollected,collected, andand thethe systemsystem cancan provide provide appropriateappropriatefollowfollow--upup formsforms oror reportsreports onon thethe flyfly..
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Process ControlProcess Control
ExpertExpert systemssystems havehave aa long,long, provenproven historyhistory ofof useuse
inin controllingcontrolling processes processes toto detectdetect andand correctcorrect
problemsproblems beforebefore theythey becomebecome seriousserious.. FromFrom DuPontDuPonttoto EastmanEastman Chemical,Chemical, manymany ofof thethe majormajor industrialindustrial
companiescompanies relyrely onon expertexpert systemssystems.. TheyThey runrun invisiblyinvisibly
inin thethe background background toto analyzeanalyze variousvarious datadata tagstags
throughoutthroughout aa processprocess andand alertalert operatorsoperators ofof potentialpotentialproblemsproblems..
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Advantages ofExpert SystemsAdvantages ofExpert Systems
PermanencePermanence ExpertExpert systemssystems dodo notnot forget,forget, butbut
humanhuman expertsexperts maymay
ReproducibilityReproducibility ManyMany copiescopies ofof anan expertexpert systemsystem
cancan bebe made,made, butbut trainingtraining newnew humanhuman expertsexperts isis timetime--consumingconsuming andand expensiveexpensive
IfIf therethere isis aa mazemaze ofof rulesrules (e(e..gg.. taxtax andand auditing),auditing),
thenthen thethe expertexpert systemsystem cancan unravelunravel thethe mazemaze
EfficiencyEfficiency cancan increaseincrease throughputthroughput andand decreasedecreasepersonnelpersonnel costscosts
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EfficiencyEfficiency cancan increaseincrease throughputthroughput andand decreasedecrease
personnelpersonnel costscosts Although expert systems are expensive to build andAlthough expert systems are expensive to build and
maintain, they are inexpensive to operatemaintain, they are inexpensive to operate
Development and maintenance costs can be spreadDevelopment and maintenance costs can be spread
over many usersover many users
The overall cost can be quite reasonable whenThe overall cost can be quite reasonable when
compared to expensive and scarce human expertscompared to expensive and scarce human experts
Cost savings:Cost savings:
WagesWages-- (elimination of a room full of clerks)(elimination of a room full of clerks)
Other costsOther costs -- (minimize loan loss)(minimize loan loss)
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ConsistencyConsistency WithWith expertexpert systemssystems similarsimilar
transactionstransactions handledhandled inin thethe samesame wayway.. TheThe systemsystemwillwill makemake comparablecomparable recommendationsrecommendations forfor likelike
situationssituations..
HumansHumans areare influencedinfluenced byby
RegencyRegency effectseffects (most(most recentrecent informationinformation havinghaving aa
disproportionatedisproportionate impactimpact onon judgment)judgment)
PrimacyPrimacy effectseffects (early(early informationinformation dominatesdominates thethe
judgment)judgment)..
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DocumentationDocumentation AnAn expertexpert systemsystem cancan provideprovide
permanentpermanent documentationdocumentation ofof thethe decisiondecision processprocess CompletenessCompleteness AnAn expertexpert systemsystem cancan reviewreview allall thethe
transactions,transactions, aa humanhuman expertexpert cancan onlyonly reviewreview aa
samplesample
TimelinessTimeliness FraudFraud and/and/ oror errorserrors cancan bebe preventedprevented..
InformationInformation isis availableavailable soonersooner forfor decisiondecision makingmaking
BreadthBreadth -- TheThe knowledgeknowledge ofof multiplemultiple humanhuman expertexpert
cancan bebe combinedcombined toto givegive aa systemsystem moremore breadthbreadth thatthat aasinglesingle personperson isis likelylikely toto achieveachieve
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Reduce risk of doing businessReduce risk of doing business
Consistency of decision makingConsistency of decision makingDocumentationDocumentation
Achieve ExpertiseAchieve Expertise
EntryEntry barriersbarriers ExpertExpert systemssystems cancan helphelp aa firmfirm
createcreate entryentry barriersbarriers forfor potentialpotential competitorscompetitors
DifferentiationDifferentiation InIn somesome cases,cases, anan expertexpert systemsystem
cancan differentiatedifferentiate aa productproduct oror cancan bebe relatedrelated toto thethe
focusfocus ofof thethe firmfirm
ComputerComputer programsprograms areare bestbest inin thosethose situationssituations wherewhere
therethere isis aa structurestructure thatthat isis notednoted asas previouslypreviously
existingexisting oror cancan bebe elicitedelicited
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Disadvantages ofExpert SystemDisadvantages ofExpert System
CommonCommon sensesense InIn additionaddition toto aa greatgreat dealdeal ofof
technicaltechnical knowledge,knowledge, humanhuman expertsexperts havehave
commoncommon sensesense.. ItIt isis notnot yetyet knownknown howhow toto givegive
expertexpert systemssystems commoncommon sensesense..
CreativityCreativity --HumanHuman expertsexperts cancan respondrespond creativelycreatively toto
unusualunusual situations,situations, expertexpert systemssystems cannotcannot..
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LearningLearning --Human experts automatically adapt toHuman experts automatically adapt tochanging environments, expert systems must be explicitlychanging environments, expert systems must be explicitly
updated. Caseupdated. Case--based reasoning and neural networks arebased reasoning and neural networks aremethods that can incorporate learning.methods that can incorporate learning.
SensoryExperienceSensoryExperience-- Human experts have available toHuman experts have available to
them a wide range of sensory experience; expert systemsthem a wide range of sensory experience; expert systemsare currently dependent on symbolic input.are currently dependent on symbolic input.
DegradationDegradationExpert systems are not good atExpert systems are not good at
recognizing when no answer exists or when the problemrecognizing when no answer exists or when the problemis outside their area of expertise.is outside their area of expertise.