/LMAR=0/XLINE=3/USET=11␈↓ α,␈↓␈↓ ⊂F1


␈↓ α,␈↓α␈↓ ∧{Arti≡cial Intelligence, Expert Systems and Common Sense

␈↓ α,␈↓α␈↓ ε5by John McCarthy, Stanford University

␈↓ α,␈↓␈↓ α|I␈α∀suppose␈α∀most␈α∀of␈α∀you␈α∀are␈α∀from␈α∀industry␈α∀and␈α∀are␈α∀mainly␈α∀interested␈α∀in␈α∀the␈α∀possibilities␈α∀of
␈↓ α,␈↓applying␈α⊂arti≡cial␈α⊂intelligence␈α⊂technology.␈α⊂ Nevertheless,␈α⊂I␈α⊂want␈α⊂to␈α⊂begin␈α⊂by␈α⊂saying␈α⊂what␈α⊂kind␈α⊂of
␈↓ α,␈↓science we are talking about.

␈↓ α,␈↓␈↓ α|Arti≡cial␈α⊗intelligence␈α⊗is␈α⊗the␈α⊗science␈α⊗involved␈α⊗in␈α⊗making␈α⊗machines,␈α⊗i.e.␈α⊗computers,␈α⊗behave
␈↓ α,␈↓intelligently.␈α∪ Many␈α∪people,␈α∪hearing␈α∪that,␈α∪ask␈α∪for␈α∪a␈α∪de≡nition␈α∪of␈α∪intelligence.␈α∪ I␈α∪can't␈α∪give␈α∪one,
␈↓ α,␈↓and I'll digress into philosophy in order to say why not.

␈↓ α,␈↓␈↓ α|``Intelligence''␈α∃isn't␈α∃a␈α∃de≡ned␈α∃concept.␈α∃ It's␈α∃what␈α∃philosophers␈α∃have␈α∃come␈α∃to␈α∃call␈α∃a␈α∃␈↓↓natural
␈↓ α,␈↓↓kind␈↓.␈α∪ Namely,␈α∪␈↓↓intelligence␈↓␈α∪is␈α∪the␈α∪name␈α∪of␈α∪a␈α∪phenomenon,␈α∪and␈α∪to␈α∪provide␈α∪a␈α∪correct␈α∪de≡nition,
␈↓ α,␈↓would␈α⊃require␈α⊃knowing␈α⊃all␈α⊃about␈α⊃that␈α⊃phenomenon.␈α⊂ Therefore,␈α⊃instead␈α⊃of␈α⊃de≡ning␈α⊃intelligence,
␈↓ α,␈↓all that can be done at the present state of knowledge is to tell you something about it.

␈↓ α,␈↓␈↓ α|Here are some facts about intelligence in general and AI in particular.

␈↓ α,␈↓␈↓ α|1.␈α→Intelligence␈α→is␈α→a␈α→property␈α→of␈α→systems␈α→that␈α→achieve␈α→goals␈α→and␈α→maintain␈α→themselves␈α→in
␈↓ α,␈↓complex␈α∀environments␈α∀by␈α∀using␈α∀knowledge␈α∀about␈α∀the␈α∀environment␈α∀in␈α∀general␈α∀and␈α∀also␈α∀about
␈↓ α,␈↓the␈α∂particular␈α∂situation.␈α∂ The␈α∂processes␈α∂that␈α∂use␈α∂the␈α∂knowledge␈α∂often␈α∂predict␈α∂the␈α∂consequences␈α∂of
␈↓ α,␈↓actions and other events.

␈↓ α,␈↓␈↓ α|What␈α⊂methods␈α⊂an␈α⊂intelligence␈α⊂has␈α⊂to␈α⊂use␈α⊂obviously␈α⊂depends␈α⊂on␈α⊂what␈α⊂kinds␈α⊂of␈α⊂problems␈α⊂are
␈↓ α,␈↓presented␈α)by␈α)the␈α(its␈α)environment.␈α) However,␈α)human␈α)physical␈α)environments,␈α)abstract
␈↓ α,␈↓mathematics and games present more similar problems than might be imagined.

␈↓ α,␈↓␈↓ α|2.␈α→Intelligence␈α→involves␈α→abstract␈α→properties␈α→independent␈α→of␈α→whether␈α→the␈α→goals␈α→are␈α→being
␈↓ α,␈↓achieved␈α∪by␈α∪humans,␈α∪by␈α∪Martians␈α∪or␈α∪by␈α∪machines.␈α∪ A␈α∪large␈α∪part␈α∪of␈α∪the␈α∪theory␈α∪of␈α∪intelligence
␈↓ α,␈↓has,␈α⊂for␈α⊂this␈α⊂reason,␈α⊂a␈α⊂mathematical␈α⊂character.␈α⊂ Certain␈α⊂computational␈α⊂means␈α⊂are␈α⊂required␈α⊂to␈α⊂to
␈↓ α,␈↓decide what to do in certain situations regardless of who or what is doing the deciding.

␈↓ α,␈↓␈↓ α|3.␈α⊃Intelligence␈α⊃isn't␈α⊃a␈α⊃unitary␈α⊃phenomenon.␈α⊃ There␈α⊃are␈α⊃a␈α⊃variety␈α⊃of␈α⊃intellectual␈α⊃mechanisms
␈↓ α,␈↓and␈α⊂we␈α⊂understand␈α⊂some␈α⊂of␈α⊂them.␈α⊂ We␈α⊂can␈α⊂make␈α⊂computers␈α⊂perform␈α⊂impressively␈α⊂on␈α⊂tasks␈α⊂that
␈↓ α,␈↓only␈α require␈α the␈α mechanisms␈α we␈α understand.␈α  Tasks␈α that␈α require␈α mechanisms␈α we␈α don't
␈↓ α,␈↓understand are beyond present technology.

␈↓ α,␈↓␈↓ α|4.␈α Having␈α fast␈α computers␈α with␈α big␈α memories␈α can␈α partially␈α compensate␈α for␈α lack␈α of
␈↓ α,␈↓understanding,␈α∀but␈α∀some␈α∀tasks␈α∀cannot␈α∀be␈α∀done␈α∀with␈α∀any␈α∀remotely␈α∀feasible␈α∀computer␈α∀until␈α∀our
␈↓ α,␈↓understanding␈α∂improves.␈α∂ In␈α∂some␈α∂areas␈α∂major␈α∂conceptual␈α∂breakthroughs␈α∂are␈α∂required,␈α∂and␈α∂it␈α∂is
␈↓ α,␈↓impossible␈α⊃to␈α⊃be␈α⊃sure␈α⊃whether␈α⊃they␈α⊃will␈α⊃take␈α⊃≡ve␈α⊃years␈α⊃or␈α⊃≡ve␈α⊃hundred.␈α⊃ Remember␈α⊃that␈α⊃it␈α⊃was
␈↓ α,␈↓100 years from Mendel to the determination of the genetic code.

␈↓ α,␈↓␈↓ α|5.␈α∪The␈α∪intelligence␈α∪of␈α∪a␈α∪program␈α∪involves␈α∪both␈α∪its␈α∪facts␈α∪and␈α∪the␈α∪procedures␈α∪it␈α∪carries␈α∪out.
␈↓ α,␈↓Without␈α⊂procedures␈α⊂nothing␈α⊂would␈α⊂ever␈α⊂happen,␈α⊂but␈α⊂progress␈α⊂in␈α⊂AI␈α⊂has␈α⊂involved␈α⊂putting␈α⊂more
␈↓ α,␈↓and␈α↔more␈α↔of␈α↔the␈α↔behavior␈α↔of␈α↔the␈α↔program␈α↔in␈α↔the␈α↔form␈α↔of␈α↔facts.␈α↔ The␈α↔information␈α↔includes
␈↓ α,␈↓general␈α⊃facts␈α⊃about␈α⊃the␈α⊃world,␈α⊃the␈α⊃facts␈α⊂about␈α⊃the␈α⊃particular␈α⊃problem␈α⊃the␈α⊃system␈α⊃is␈α⊃to␈α⊃solve␈α⊃and
␈↓ α,␈↓facts about how to carry out the reasoning.
␈↓ α,␈↓␈↓ ⊂F2


␈↓ α,␈↓␈↓ α|6.␈α⊃The␈α⊃present␈α⊃state-of-the-art␈α⊃in␈α⊃AI␈α⊃is␈α⊃characterized␈α⊃by␈α⊃certain␈α⊃successes␈α⊃and␈α⊃limitations␈α⊃in
␈↓ α,␈↓expressing␈α≠di≥erent␈α≠kinds␈α≠of␈α~facts␈α≠and␈α≠making␈α≠the␈α≠computer␈α≠carry␈α≠out␈α≠di≥erent␈α≠kinds␈α≠of
␈↓ α,␈↓reasoning.

␈↓ α,␈↓␈↓αCommon Sense␈↓

␈↓ α,␈↓␈↓ α|My␈α≤own␈α≤work␈α≤in␈α≤arti≡cial␈α≤intelligence␈α≤since␈α≤1958␈α≤has␈α≤concerned␈α≤the␈α≤goal␈α≤of␈α≤making
␈↓ α,␈↓computer␈α∃programs␈α∃with␈α∃␈↓↓common␈α∃sense␈↓.␈α∃ By␈α∃this␈α∃I␈α∃mean␈α∃a␈α∃program␈α∃with␈α∃the␈α∃knowledge␈α∃and
␈↓ α,␈↓reasoning␈α⊗ability␈α⊗possessed␈α⊗by␈α⊗any␈α⊗human␈α⊗who␈α⊗isn't␈α⊗feeble-minded.␈α⊗ This␈α⊗seemed␈α⊗di≠cult␈α⊗in
␈↓ α,␈↓1958,␈α~and␈α~it␈α~is␈α→still␈α~di≠cult.␈α~ Fortunately,␈α~for␈α~the␈α~application␈α~of␈α~AI␈α~to␈α~practical␈α~problems,
␈↓ α,␈↓common sense isn't always required.

␈↓ α,␈↓␈↓ α|What is common sense?

␈↓ α,␈↓␈↓ α|We still can't fully characterize it, but we can describe some of its components.

␈↓ α,␈↓␈↓ α|1. Knowledge of the e≥ects of events including especially the e≥ects of actions.

␈↓ α,␈↓examples: e≥ects of travelling, e≥ect of sitting or standing, dying

␈↓ α,␈↓␈↓ α|2. knowledge of space and objects

␈↓ α,␈↓␈↓ α|3.␈α∃relations␈α∃between␈α∃appearance␈α∃and␈α∃reality␈α∃This␈α∃version␈α∃of␈α∃hannov[w86,jmc]␈α∃pubbed␈α∃at
␈↓ α,␈↓13:54 on April 6, 1986.
/FONT#0=BASL10[300,SYS]/FONT#1=BASI10[300,SYS]=acdegiklmnorstuu/FONT#2=BASB10[300,SYS]=≡ ,ACEIJMSUabcdefghilmnoprstvxyy