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Old April 9th, 2009 #99
psychologicalshock
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Join Date: Jun 2007
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Quote:
Originally Posted by Larry Heinberg View Post
I largely agree with your argument. I do not agree that it is the same as his.
Fine, take it up with him.

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No, but it is a false comparison.

A truer comparison would be this:
I have a bag with some coloured marbles in it. Among others, there are red marbles and blue marbles. There are more red marbles than blue marbles.

What is the probability of drawing a red marble? Greater than the probability of drawing a blue marble. We cannot say the exact probabilities, or even how much more likely we are to draw a red marble than a blue one, given the information provided.
Are you saying that a detailed FBI report of exact crime per unit of population isn't precise enough? That's just the lower bound too since true crime is significantly higher.

By the way your example doesn't make sense, if the chance is higher then how did you find out it's higher ? By experimenting? If you experiment (Do it 1 by 1) you'll get an exact number until you at least get 50% Blue or red you cannot say with 100% that the probability is higher or lower. Your argument is actually nonsense and irrelevant , well done. Even if it is true using approximations it still doesn't contradict my argument or the original argument since exactness isn't needed for the argument made merely a more than or less than.

Might be a bit late to point it out but his argument actually is just a statistical syllogism so your goal isn't actually to target validity but to target accuracy.




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Was there some point you wanted to make here? I have said which argument I believe is invalid.
That isn't a logical argument, it's merely a statement of reason with an argument within it.









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I do know what validity is. Validity is the quality possessed by an argument whose conclusion must be true if its premises are true. The premises of his argument have little bearing on its conclusion - they could be true and the conclusion false, they could be false and the conclusion true. His argument is not valid.
No his premises lead exactly to the conclusion, I have reconstructed the argument and took out reason, that is his argument and it is perfectly sensical. What you said isn't true since as your demonstration showed the same line of reasoning is true for men. So nice try but no cigar. The statement is accurate as long as the group does actually commit more crime.

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Statistical data does not make a valid argument. The fact that you mention them shows that you are using a different meaning of the term "validity".
Statistics and probability are actually an excellent argument and commonly used in inductive logic.