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Dr. Bob is Robert Hsiung, MD,
bob@dr-bob.orgShown: posts 18 to 42 of 69. Go back in thread:
Posted by Larry Hoover on December 3, 2005, at 14:38:51
In reply to Re: ...addendum, posted by alexandra_k on December 2, 2005, at 1:05:25
> > In practical terms, we might conclude that it is false,
But really,
> It is inductively weakYa, that's what I meant. Though I think my 'non demonstrare' looks cooler. ;-)
Lar
Posted by linkadge on December 3, 2005, at 14:38:51
In reply to Re: ...or overgeneralizing?, posted by alexandra_k on December 2, 2005, at 0:24:00
Of course, as an argument of induction, one is missing the crutial "induction step".
If we ordered the members of this site 1..n, proving the statement is true for 1, is not sufficiant to show that it is true for all other n.
There would need to be an induction step. Ie person n thinks he is smarter than his doctor -> person n 1 thinks he is smarter than his doctor. Then proof would follow based the presence of an iscolated case, and induction step.
P.S. This whole thread is nonsence.
Linkadge
Posted by linkadge on December 3, 2005, at 14:38:52
In reply to Re: ...addendum, posted by Larry Hoover on December 2, 2005, at 0:35:11
There is an implication statement being made.
p = I think I am smarter than my doctor
q = All here thinks himself smarter than
his doctor.Statement p -> q.
To proove false, simply disprove contrapositive arguement.
Ie show. Not q -/-> Not p
Where not q, is shown by the existence of a memeber that doesn't think himself smarter than his doctor. Yet dispite this, p still holds.
Hence we have shown.
Not q -/-> Not p
Which implies
p -/-> q
Linkadge
Posted by Larry Hoover on December 3, 2005, at 14:38:52
In reply to Re: ...addendum, posted by linkadge on December 2, 2005, at 11:17:23
> There is an implication statement being made.
>
> p = I think I am smarter than my doctor
> q = All here thinks himself smarter than
> his doctor.
>
> Statement p -> q.
>
> To proove false, simply disprove contrapositive arguement.
>
> Ie show. Not q -/-> Not p
>
> Where not q, is shown by the existence of a memeber that doesn't think himself smarter than his doctor. Yet dispite this, p still holds.
>
> Hence we have shown.
>
> Not q -/-> Not p
>
> Which implies
>
> p -/-> q
>
>
>
> LinkadgeYa, but he didn't say 'all'. That's what I was getting at when I said his use of 'most' meant a single dispositive case did not falsify the argument. Most is an existential quantifier.
Lar
Posted by linkadge on December 3, 2005, at 14:38:52
In reply to Re: ...addendum » linkadge, posted by Larry Hoover on December 2, 2005, at 13:49:43
The assumption is that more than half of people on this board think the same way as the poster, regarding their doctors.
That is a statment, requiring justification.
Unless, an association between Ace's decisions and other posters' decisions can be demonstrated, the only way to proof or disprove the statement is with a counterexample.
Linkadge
Posted by alexandra_k on December 3, 2005, at 14:38:52
In reply to Re: ...addendum, posted by linkadge on December 2, 2005, at 14:13:33
> the only way to proof or disprove the statement is with a counterexample.
statements aren't 'proved' or 'disproved' they are 'true' or 'false' (or 'neither true nor false' - but not in a two valued logic. in a two valued logic they are either true or false and not both at the same time).
lets imagine a possible world in which...
it is TRUE that the poster thinks he is smarter than his p-doc... (so the premiss is true)
AND
it is FALSE that most babblers think they are smarter than their p-docs... (51% do not think they are smarter than and thus the conclusion is false)then you would have a 'counter-example'
a situation where the premiss is true (the poster thinks he is smarter than his p-doc) AND the conclusion false (because most babblers do not think they are smarter than their p-doc).
However, that counter-example only works to show that the argument is DEDUCTIVELY INVALID. Which just means... that it IS possible (without contradiction) for the premises to be true while the conclusion is false.But we decided already that it wasn't so charitable to interpret it as an attempt at a deductively valid argument...
With respect to an inductive argument...
If one individual has property p
Is it more likely to be true or false that most individuals have property p?
It doesn't really seem more likely to be true that MOST individuals have that property (if the ONLY reason / premiss is that one individual has that property)
and hence...
the premiss doesn't give us good reason to believe the conclusion is more likely true than false
hence...
it isn't inductively forceful...It is about the weakest form of inductive argument possible because it goes from one to most. worse still would be from one to all. slightly better would be most to one. best (and deductively valid or 100% inductively forceful would be all to one)
:-)
Posted by alexandra_k on December 3, 2005, at 14:38:52
In reply to Re: ...addendum, posted by linkadge on December 2, 2005, at 11:17:23
> There is an implication statement being made.
> p = I think I am smarter than my doctor
> q = All here thinks himself smarter than
> his doctor.> Statement p -> q.
Yes, you are right.
That seems to be a legitimate interpretation :-)> To proove false, simply disprove contrapositive arguement.
sh*t.
you are right
:-)
well done.
Posted by alexandra_k on December 3, 2005, at 14:38:52
In reply to Re: ...addendum » linkadge, posted by alexandra_k on December 2, 2005, at 14:58:29
though...
you showed it to be deductively invalid...
and we already decided
(well, i did)
that it was more charitably interpreted as a inductive argument (where the majority of inductive arguments - and some inductively forceful arguments - are deductively invalid)
;-)
Posted by alexandra_k on December 3, 2005, at 14:38:52
In reply to We have some ppl with a lot of time here, posted by UgottaHaveHope on December 2, 2005, at 2:02:40
> and from the looks of it, law students, stating a case of "deductive reasoning"
:-O
philosophy.
:-(
Posted by alexandra_k on December 3, 2005, at 14:38:52
In reply to Re: ...addendum » linkadge, posted by Larry Hoover on December 2, 2005, at 13:49:43
> Most is an existential quantifier.
:-)
yes.
it is.i got what you meant when you explained it in english.
it is just the technical terminology that has to be learned by...
rote really...but why bother when you get it in english?
mostly for purposes of explaining to others is all...
Posted by linkadge on December 3, 2005, at 14:38:52
In reply to Re: ...addendum » linkadge, posted by alexandra_k on December 2, 2005, at 14:51:36
You are right, that statements are either true or false.
But if you have a statement that has not been proven true or false, then it cannot be deemed true or false.
There could be a third yet undescoverfed relation factor.
Say, if we knew that, due to Ace's popularity, there was a statistic likelyhood that others would believe the same.
If this were true, then the statement would be true.
So simple if, then statements cannot be discounted based on the fact that a connection cannot be seen.
Linkadge
Posted by alexandra_k on December 3, 2005, at 14:38:52
In reply to Re: ...addendum, posted by linkadge on December 2, 2005, at 16:34:14
> You are right, that statements are either true or false.
in a two-valued logic your statement is true
this is the principle of bivalenceEITHER T OR F AND NOT BOTH
> But if you have a statement that has not been proven true or false, then it cannot be deemed true or false.we do not know whether tomorrow will be the end of the world or not. the statement 'the world will end at time t' is either true or false independently of what (if anything) we can know about it...
we might not know whether a certain mathematical theorum is true or false, but it is either true or false independently of whether we ever manage to figure that out or not...> There could be a third yet undescoverfed relation factor.
many valued logics reject the principle of bivalence: that every proposition is either true or false and not both. there are two forms of rejection: the first is the idea that there are more values than these. the second is that propositions may be neither true nor false (lacking a truth value).
This manouver is to deal with some special kinds of statements such as
'the present king of france is bald'.
It is not T, so it must be F.
but to say it is F is to imply / logically entail that
'there is a present king of france and that present king of france is bald' is T.
but of course 'there is a present king of france' is F. and thus 'there is a present king of france and that king of france is bald' is F.there are contradictions in two-valued logic (which is a disgrace)
> Say, if we knew that, due to Ace's popularity, there was a statistic likelyhood that others would believe the same.
(P1) Ace is a popular person
(P2) Most babblers believe what a popular person believes
(P3) Ace is a babbler and Ace believes 'I am smarter than my p-doc'
______________________________________________
(C) Most (the same referent as P3) babblers believe 'I am smarter than my p-docThat argument is deductively valid.
(It is impossible to describe a situation where the premises are true and the conclusion false without contradiction)The relationship between the premises and conclusion is very tight
The trouble is that if people believe premiss 1 or 2 (or both) to be false then they have no reason to believe the conclusion on the basis of the argument.
(Regardless of whether the conclusion is true or not people have no reason to believe the conclusion on the basis of the argument and thus the argument is not rationally persuasive)
In order for a valid argument to be rationally persuasive
Other people would have to be likely to accept the truth of the premises
If you have a valid argument and people believe the premisses are all true then they would be endorsing contradiction to deny the conclusion
> If this were true, then the statement would be true.The argument would be deductively valid / its degree of inductive force would be 100%
But...
If we think either premiss 1 or 2 (or both) are false then we have no reason to come to believe the conclusion.
> So simple if, then statements cannot be discounted based on the fact that a connection cannot be seen.P1) grass is green
______________
C) the sun is hotThere is no contradiction in imagining a possible world with green grass and no sun or a cold sun or whatever. The argument is not deductively valid. The argument is not rationally persuasive (because it is an attempt at a deductive argument and it is invalid).
Yet...
The sun is hot.
We just don't have reason to believe the truth of the conclusion
ON THE BASIS OF
The reason (premiss) provided.
Posted by CamW on December 3, 2005, at 14:38:53
In reply to Re: ...addendum » linkadge, posted by alexandra_k on December 2, 2005, at 22:10:28
It has been my experience, that, on this board, 50% of posters are of below average intelligence.
;-P
- Cam (I believe that I need to thank Arthur C. Clark for this one)
P.S. Think about it before getting nasty. - C.
Posted by alexandra_k on December 3, 2005, at 14:38:53
In reply to Looking at it another way...., posted by CamW on December 3, 2005, at 0:42:38
ROFL
thanks :-)
Posted by linkadge on December 3, 2005, at 14:42:08
In reply to Re: ...addendum » linkadge, posted by alexandra_k on December 2, 2005, at 22:10:28
Say you are testing a person to see if they are HIV positive. We know that they are either positive or negative, but the test itself could come back inconclusive, meaning that it is impossable to tell which one it is at this time.
I'm not disputing the fact that the person is still either positive or negative however.
Linkadge
Posted by Larry Hoover on December 3, 2005, at 14:42:08
In reply to Looking at it another way...., posted by CamW on December 3, 2005, at 0:42:38
> It has been my experience, that, on this board, 50% of posters are of below average intelligence.
>
> ;-P
>
> - CamAnd 50% of pharmacists graduated in the bottom half of their class. ;-)
Good to see you, Cam. Are you coming to this year's Babble Reunion or whatever they're calling it? Babble Birthday?
Lar
Posted by zenhussy on December 3, 2005, at 14:42:08
In reply to Looking at it another way...., posted by CamW on December 3, 2005, at 0:42:38
interesting observation there Cam. ;-)
Posted by phil on December 3, 2005, at 15:25:08
In reply to Looking at it another way...., posted by CamW on December 3, 2005, at 0:42:38
Anyone have a calculator?
Posted by pseudoname on December 3, 2005, at 16:31:25
In reply to Looking at it another way...., posted by CamW on December 3, 2005, at 0:42:38
> It has been my experience, that, on this board, 50% of posters are of below average intelligence.
> ;-PThat's possible, but it wouldn't always be true, even taking the average of only the people who post on this board (not the average of all people everywhere). Consider:
Say there are 100 people who post. On some scale of intelligence that has scores of 0-10...
90 posters have scores of 10.0
10 posters have scores of 9.0
The average intelligence is then 9.9, and 90% of posters on the board have ABOVE-average intelligence.Or say of 100 people posting on some other site...
1 poster has a score of 10.0.
99 posters have scores of 1.0.
The average intelligence is then 1.09, and 99% of posters on that board have BELOW-average intelligence.The statement, "On this board, 50% of posters are of below MEDIAN intelligence," would always be true (+/- 1 poster).
Posted by pseudoname on December 3, 2005, at 16:40:29
In reply to Re: Looking at it another way.... » CamW, posted by Larry Hoover on December 3, 2005, at 13:25:36
I forgot to add (to my preceding post about averages) that Larry's statement...
> And 50% of pharmacists graduated in the bottom half of their class.
...is, I think, always true, since it refers to a percentile, not an average.
Posted by Gabbix2 on December 3, 2005, at 17:54:20
In reply to 99% can be below-average » CamW, posted by pseudoname on December 3, 2005, at 16:31:25
I think that was the point, or the meaning of the comment.. which was meant tongue-in-cheek.
Posted by alexandra_k on December 3, 2005, at 17:54:48
In reply to ...I should've added... » Larry Hoover, posted by pseudoname on December 3, 2005, at 16:40:29
heh heh.
math...:-)
Posted by alexandra_k on December 3, 2005, at 17:55:32
In reply to Re: 99% can be below-average » pseudoname, posted by Gabbix2 on December 3, 2005, at 17:54:20
> I think that was the point, or the meaning of the comment.. which was meant tongue-in-cheek.
yeah. and i don't think the post that started the thread was really intended as an argument either...
Posted by Gabbix2 on December 3, 2005, at 18:47:51
In reply to Re: 99% can be below-average » Gabbix2, posted by alexandra_k on December 3, 2005, at 17:55:32
I don't think so either.. :)
Posted by pseudoname on December 3, 2005, at 22:01:27
In reply to Re: 99% can be below-average » pseudoname, posted by Gabbix2 on December 3, 2005, at 17:54:20
> Re: 99% can be below-average » pseudoname
> I think that was the point, or the meaning of the comment.. which was meant tongue-in-cheek.Gabbix...
I was sorry to see you thought my post was not appropriate.
You're right, Cam's post was tongue-in-cheek. But why do you think I didn't understand that?
This entire thread (that got moved) is playful with math & logic.
My post also plays with numbers, words, and rules. I thought it, too, *might* be pleasurable for people who enjoy logic games and math. At least it could be interesting.
I really am sorry. (I'm not being sarcastic.) I guess I'm still too socially tone-deaf to see why the other 29 logic-laden, playfully-correcting-each-other, back-&-forth posts are acceptable (including my earlier ones, I guess) but my last observation was not.
I'm open to anyone's suggestions, but please be gentle.
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