lindek@seismo.CSS.GOV@cs.strath.ac.uk (03/02/87)
Look, WORLD, here is a little default reasoning exercise: 95% of elephants have color grey. 40% of Royal Elephants have color yellow. Clyde is a Royal Elephant. The color of Clyde is likely to be: a) Grey b) Yellow c) Red d) Unknown Dekang Lin Dept. of CS Univ. of Strathclyde 26 Richmond Street Glasgow, G1 1XH, U.K. E-mail: ....!siesmo!mcvax!ukc!strath-cs!lindek
lindek@cs.strath.ac.UK.UUCP (04/01/87)
In article <8703021016.AA22995@stracs.cs.strath.ac.uk> lindek@seismo.CSS.GOV@cs.strath.ac.uk (Dekang Lindek) writes: >Look, WORLD, here is a little default reasoning exercise: > >95% of elephants have color grey. >40% of Royal Elephants have color yellow. >Clyde is a Royal Elephant. > >The color of Clyde is likely to be: > a) Grey b) Yellow c) Red d) Unknown > There are several bugs here: 1) 'most likely' should be used in place of 'likely' to make the question clear. 2) 'Unknown' should not be one of the choices because neither 'likely to be unknown' nor 'most likely to be unknown' makes any sense. It is a fact that the color of Clyde is unknown, otherwise we won't need to guess it. 3) 'elephants have color grey' sounds like Next-Generation-Database English. 4) 'Lindek' is his E-name, not surname. 5) (This place is reserved for future use) After fixing the first four bugs, we could make the following inference: #define confidence probability proposition confidence (1) A Royal Elephant is yellow. .40 (2) A Royal Elephant is not yellow .60 (3) (An elephant is not yellow) ==> (The elephant is grey) .95~1.0 (4) (A Royal elephant is not yellow) ==> (A Royal elephant is grey) .95~1.0 (5) A Royal Elephant is grey .57~.60 (6) Clyde is a Royal Elephant. 1.0 Conclusion(subject to change without notice): Clyde is most likely to be GREY.[] Discussion: The decision becomes harder to make when the confidence of (1) is inside the interval of (5). Comments: This problem seems too technical to be discussed on the net. An opinion poll in Glasgow will definitely show that the color of Clyde is green even though it is blue on the maps. Dekang Lin Dept. of CS Univ. of StrathClyde 26 Richmond Street Glasgow G1 1XH, U.K. lindek%uk.ac.strath.cs@ucl-cs.arpa ....!seismo!mcvax!ukc!strath-cs!lindek