pedanterrific comments on Amanda Knox: post mortem

Comment author: Desrtopa 21 October 2011 04:11:36AM 2 points [-]

Well, if someone has motives for making a statement aside from its truth, then it will tend to decrease the degree to which the statement is conditional on the truth, and thus its weight as evidence. So while "A has ulterior motives for saying X, therefore X is false" is certainly fallacious, "A has ulterior motives for saying X, therefore decrease the weight of evidence you assign to X" is not. It can, however, be such an insignificant presentation of evidence as to be distracting and logically rude.

Comment author: pedanterrific 21 October 2011 04:19:11AM 1 point [-]

Yes, this is what I'm getting at.

And when X = [the sky is blue], you shouldn't decrease the weight of evidence you assign to X at all, because the statement was never evidence of that in the first place: it's just remarking on something obvious.

Comment author: Desrtopa 21 October 2011 04:32:04AM 5 points [-]

And when X = [the sky is blue], you shouldn't decrease the weight of evidence you assign to X at all, because the statement was never evidence of that in the first place: it's just remarking on something obvious.

It's still evidence; it's more likely conditional on the sky being blue than conditional on the sky not being blue. But the weight of one remark is very weak evidence compared to that which is already available to you.

If everyone started asserting that the sky was green, that it had always been green, and that you must be delusional for remembering otherwise, you might be wiser to doubt the input of your own senses.

Although if you're questioning your own sanity, I suppose it might be likelier that you're imagining that everyone has started claiming that the sky is green than that you're imagining that it's blue and that people ever used to say so.

Comment author: pedanterrific 21 October 2011 04:41:44AM 1 point [-]

Okay, maybe "at all" was an exaggeration.

And this reminds me of a post a while back about the reliability of peer-reviewed science journals over your own senses. (The catch being that you can't extract information from science journals without using your senses.)

Comment author: brazil84 21 October 2011 04:27:57AM -1 points [-]

By the way, can you explain to me what you think it is that I am (or should be) trying to accomplish here?

I'm not so sure bringing this to people's attention is in your best interests.

What interests are you referring to?

Comment author: pedanterrific 21 October 2011 04:36:43AM 0 points [-]

I assumed you were playing a status game; all "oh woe is me, wedrifid is unfairly persecuting me for besting him in an argument (which is blurred by the passage of time and to which I will not provide a link)". In which case, bringing up that specific argument - in which you are clearly in the wrong - would seem to work at cross-purposes.

That's just the impression I was operating under when I wrote that comment, mind.

Comment author: brazil84 21 October 2011 04:42:18AM -2 points [-]

I assumed you were playing a status game;

Lol, thanks for your concern about my motivations.

Anyway, I'm pretty confident that I was in the right in my previous exchange but I prefer to discuss it in the previous thread. If you see a flaw in an argument I presented, feel free to present it (preferably there). I promise to consider it in good faith.

Comment author: brazil84 21 October 2011 04:24:12AM -2 points [-]

Let me put it this way: the fact that you reached an incorrect conclusion and acted like you didn't get what was wrong with that was sufficient reason for wedrifid to act as he did. To impute other motives for no apparent reason is... well, it's rude.

I'm not sure what your point is here. Wedrifid seemed to be saying that it was necessarily wrong for me to put little weight on the opinions of other posters. In essence, I asked him to spell out his argument. At that point, he got pretty nasty. And as noted, he didn't actually make an argument on the merit's of Knox's guilt or innocence. Nor did he make an actual argument for why I should have put more weight on the opinions of other posters. He asserted his conclusion.

When somebody makes a statement like that, as if it's from authority, it's reasonable to point it out if they have an agenda.

Comment author: pedanterrific 21 October 2011 04:48:56AM * 0 points [-]

And as noted, he didn't actually make an argument on the merit's of Knox's guilt or innocence.

For one thing, he wasn't really talking to you, but to people already convinced of her innocence.

Nor did he make an actual argument for why I should have put more weight on the opinions of other posters.

Once you accept the implications of Aumann's Agreement Theorem, the only reason not to would seem to be extremely low opinions of their intelligence and rationality.

It's a combination of having little respect for the opinions of anonymous internet posters

Well, guess that answers that.

Comment author: brazil84 21 October 2011 05:06:09AM -2 points [-]

For one thing, he wasn't really talking to you, but to people already convinced of her innocence.

I'm not sure what difference this makes. He publicly pronounced my earlier conclusion to be insane, in response to a post I made. When somebody behaves like that, it's reasonable to point out that there may be some personal animus involved.

Well, guess that answers that.

FWIW, the only person here whose opinion I have some degree of respect for is Eliezer and even he has lost a lot of his edge over the years. Not that it matters, since I mainly go by peoples' actual arguments on the merits and not their opinions.

Comment author: bigjeff5 07 November 2011 11:33:00PM 0 points [-]

I really think you aught to start reading through the sequences on rationality and biases, but you might need to start with basic logic first.

If you've read them already, then I'm just shocked. Maybe read them again? I don't know what else to suggest.

The fact that you can continue to argue that Knox and Sollecito are guilty with a 90% confidence, after it has been proven within the limits if modern science's ability to prove anything, that there is not one trace of physical evidence that Knox and Sollecito were involved in the murder, is just mind blowing to me.

All of the arguments presented to you are going to fail, because they are based on critical thinking and logic, and you don't seem to be capable of these.

To repeat a previous poster, the fact that you are a lawyer and show such a complete inability to reason (to the point that you think logical fallacies are reasonable arguments in some cases*) is downright scary.

*Motive is reasonable evidence for adjusting credibility, but it is always weak and often insignificant. It should never, ever be used to claim an argument is false. The most you can claim is uncertainty of the truth of an argument if the motive is sufficiently strong.

Comment author: dlthomas 10 November 2011 09:01:44PM 2 points [-]

[I]t has been proven within the limits if modern science's ability to prove anything, that there is not one trace of physical evidence that [some specific facts about a specific event].

This seems like ridiculous hyperbole - science has far more ability to "prove" things that are repeatable than unrepeatable.

Comment author: bigjeff5 11 November 2011 01:03:15AM 0 points [-]

You are absolutely correct.

I should have said "anything of this nature", my mistake.

Comment deleted 10 November 2011 09:15:11PM * [-]

Comment author: dlthomas 10 November 2011 09:21:35PM 0 points [-]

I did not mean to say, "there is no evidence of absence of guilt", or even "there is not overwhelming evidence of absence of guilt" - not really having looked directly at evidence myself, it would be silly for me to weigh in either way. I was just objecting to the hyperbole: science's ability to "prove" (or provide evidence for) the premise that Newtonian gravity approximately holds for speeds and masses typically involved in human activity on the surface of the earth seems much, much greater than sciences ability to "prove" (or provide evidence for) anything particular feature of a past event.

Comment author: PhilosophyTutor 10 November 2011 10:46:54PM 0 points [-]

This seems like ridiculous hyperbole - science has far more ability to "prove" things that are repeatable than unrepeatable.

You are completely correct.

In the spirit of constructing the best possible argument to engage with, I think we should run as if bigjeff5 had actually said exactly what he said, but appended to it "and the prior probability of the alleged crime having occurred as per the police theory is so incredibly low that nothing but physical evidence that Knox and Sollecito were involved in the murder should push our posterior probability into the >1% range", or something similar.

Comment author: Desrtopa 10 November 2011 11:42:14PM 0 points [-]

I'd say there's all sorts of non-physical evidence that would be sufficient to push our posterior probability of their guilt higher than that (insofar as any evidence in a materialistic universe can be said to be non-physical.) Email records between Knox, Sollecito and Guede discussing their plans to kill Kercher, for instance. Or if Knox or Sollecito had made statements about the circumstances of Kercher's death which forensics corroborated which they could not plausibly have made without knowledge that would require them to have been there. Even just evidence of private meetings between Knox, Sollecito and Guede, combined with enough of the warning signs for a person likely to commit murder ought to boost the likelihood that they were complicit well over 1%.

It's not that there aren't possible forms of non physical evidence that would be adequate to establish a high likelihood for their guilt, it's that such evidence is conspicuous in its absence.

Comment author: PhilosophyTutor 11 November 2011 01:09:32AM * 0 points [-]

I'd say there's all sorts of non-physical evidence that would be sufficient to push our posterior probability of their guilt higher than that (insofar as any evidence in a materialistic universe can be said to be non-physical.) Email records between Knox, Sollecito and Guede discussing their plans to kill Kercher, for instance. Or if Knox or Sollecito had made statements about the circumstances of Kercher's death which forensics corroborated which they could not plausibly have made without knowledge that would require them to have been there. Even just evidence of private meetings between Knox, Sollecito and Guede, combined with enough of the warning signs for a person likely to commit murder ought to boost the likelihood that they were complicit well over 1%

My intention was certainly to have recordings of Knox and Sollecito plotting to kill Meredith Kercher, email records of such an exchange, mobile phone calls placed to Rudy Guede and so on as physical evidence if any of them had existed. I class ones and zeroes on a hard drive or a magnetic imprint on a tape as physical evidence just as I count DNA as physical evidence.

Eyewitness evidence or police claims unsupported by physical evidence would be the kind of thing I intended to exclude by specifying physical evidence.

Comment author: dlthomas 10 November 2011 10:52:10PM * 0 points [-]

I agree that the argument should proceed that way. I was only weighing in tangentially on the rhetoric.

Comment author: brazil84 comment score below threshold [+] (101 children)

Comment author: wedrifid 10 November 2011 08:28:25PM * 1 point [-]

I want to print this comment out and frame it. This is for real, not tongue in cheek irony?

Comment author: bigjeff5 08 November 2011 07:12:21PM * 1 point [-]

Since the elimination of the faulty DNA evidence (which was previously the best evidence against them), the best evidence against Knox and Sollecito come from the police interrogation, specifically Knox's confession, and the fact that they knew the victim.

The strongest bit here is the confession, as knowing the victim is, at best, a pointer for where to look for a suspect - it is incredibly weak evidence on its own (in fact, there are dozens of people who fit better based on just knowing the victim) and does not in any way eliminate the possibility of a random stranger committing the crime. By all accounts the three got along reasonably well, if not particularly friendly to each other.

There are some interesting facts about the confession that I think you're missing:

1.) It is factually incorrect. The statements in the confession do not fit the facts of the crime. This severely damages the validity of the confession.

2.) The confession came after 24 hours of non-stop interrogation by the Italian police. There have been a number of studies that have shown that suspects become highly confused after long, intense interrogation sessions - particularly those that include sleep deprivation as was the case here. Suspects can be coerced into making whatever statements the interrogators want. In fact, in the US we have laws against this kind of treatment, including things like the right to silence and the right to have an attorney present during an interrogation to prevent exactly these scenarios. As an attorney I'd expect to know this.

Taken together, by far the most likely scenario is that the police coerced the confession out of Knox. Just on the facts relating to the interrogation alone, I'd put the likelihood that the confession was genuine at 10% at the very highest.

If the confession were genuine, we would expect some physical evidence of Knox and Sollecito at the crime scene. Given the fact that there is literally zero physical evidence of Knox and Sollecito's involvement, the likelihood that the confession is genuine must drop even further, to below 1%.

Considering the confession is about the only evidence for their involvement, I have to place the likelihood of their guilt at <1%. (There was a homeless man who claimed he saw them enter the apartment, but this is so weak as to be irrelevant given the poor track record of eyewitness accounts even immediately after a highly memorable event, the credibility of a detailed recollection of a mundane event over a year after it occurred is virtually non-existent, particularly without any evidence to back it up of any kind.)

Also, the reason I suggested you re-read the sequences is because you stated that you were 90% certain that all three were guilty, yet 90% that Guide was guilty even if the other two were not. This is a major failure in probability (and is actually a pretty common bias), as the options are Guide acted alone, or Guide acted with accomplices. Eliminating Knox and Sollecito from the equation eliminates a point of uncertainty, no matter how certain you are of Knox and Sollecito's guilt, and aught to increase your confidence in the individual assessment of Guide's guilt. Being 99% certain that Guide is guilty, and 90% certain that Guide, Knox, and Sollecito are guilty is logically consistent. Being 90% certain that Guide is guilty, yet 90% certain that all three are guilty is not logically consistent. You have to either lower you confidence in the guilt of all three, or raise your confidence in the guilt of Guide.

I may have phrased that last paragraph poorly, but most people should be able to understand it. I may edit for clarity later.

Edited to add: Here is a good article on coerced confessions, written by a forensic scientist.

Second edit, sorry, pertinent quote from the article:

When a confession is admitted and later retracted and claimed to have been made under duress, an additional question is whether the jury can understand the pressures that led up to the confession. Milgram's (1963, 1964) obedience studies suggest that, although most people may believe they personally would never succumb to pressure, their behavior in a coercive environment is to conform. Jury members may be unable to perceive how an innocent person could actually confess to something he did not do. Widespread overconfidence in personal ability to resist coercion may lead jurors to give undue and erroneous weight to a coerced confession. Expert testimony may be necessary to help jurors understand the circumstances that lead to nonvoluntary confessions, but trial courts have not always admitted such testimony.

Comment author: brazil84 10 November 2011 04:01:30PM 0 points [-]

There are some interesting facts about the confession that I think you're missing:

Not really, since I put little weight on what Knox said under interrogation. I have no problem believing that an innocent person would buckle under the pressure and point the finger at someone else. To me, what's most interesting about this "confession" was that the authorities arrested another person (the wrong person) based on Knox's statements. This is evidence that the authorities had something of an open mind about the situation.

Anyway, I disagree with you that this is the strongest piece of evidence against Knox and I think I can demonstrate it to you if you will indulge me by answering (or trying to answer) a few questions:

(1) When did Knox first become concerned about Kercher's absence?

(2) When did Sollecito and Knox first call the police and why?

(3) If it turns out that the ransacking of Romanelli's room was a staged burglary, do you agree that this is decent evidence against Knox?

Also, the reason I suggested you re-read the sequences is because you stated that you were 90% certain that all three were guilty, yet 90% that Guide was guilty even if the other two were not.

Can you show me where I did that? My recollection is I estimated roughly 99% for Guede's guilt.

I agree that it would not make sense to estimate 90% for Knox, Sollecito, and Guede to all be involved in the murder and 90% for Guede alone.

Comment author: komponisto 10 November 2011 04:22:29PM 1 point [-]

(1) When did Knox first become concerned about Kercher's absence?

(2) When did Sollecito and Knox first call the police and why?

These questions are disingenuous and pointless. If you think the answers to them are incriminating to Knox and Sollecito, then you should just state (what you believe to be) the answers and explain why they are incriminating. This is what you would do if you were arguing honestly (instead of trying to "catch" your opponent in a mistake), and it would also save time.

(3) If it turns out that the ransacking of Romanelli's room was a staged burglary, do you agree that this is decent evidence against Knox?

Of course it is, which is why the staging charge carries a burden of proof equal to that of the murder charge.

I agree that it would not make sense to estimate 90% for Knox, Sollecito, and Guede to all be involved in the murder and 90% for Guede alone.

That would make perfectly good sense. What would not make sense is 90% for all three and 90% for Guede with or without the others.

Comment author: wedrifid 10 November 2011 07:53:08PM * 0 points [-]

Preface: I disagree with brazil about basically everything he says regarding Knox and reject most of the reasoning he uses to try to argue his case. But:

These questions are disingenuous and pointless.

Disingenuous does not apply to these questions in this context. There is no feigning of naivety, ignorance or unsophistication. The questions are rhetorical, pretentious, annoying, misguided, of dubious relevance and wrapped up with a tad of snide - but not disingenuous.

continue this thread »

Comment author: brazil84 10 November 2011 05:09:12PM -1 points [-]

These questions are disingenuous and pointless.

I disagree, because I suspect that just like desrtopa, bigjeff5 does not understand the case against Knox. If he is unable to answer these questions, it will confirm my suspicions. At the moment, I am not interested in debating Knox's guilt with biggjeff5 if he hasn't bothered to study and understand the evidence against her.

Of course it is

Well do you agree that there is decent (if not compelling) evidence that the burglary was staged? For example (1) Romanelli's testimony that she found glass on top of her disturbed items; (2) Romanelli's testimony that nothing was taken from her room; and (3) Sollecito's apparent statement to the police (before Romanelli returned) that there had been a burglary but nothing was taken?

What would not make sense is 90% for all three and 90% for Guede with or without the others.

Yes, I think that's what I meant. I think I can make things simpler by laying out 4 possibilities:

(1) Guede, Knox, and Sollecito were all involved in the murder;

(2) Guede was involved in the murder but not Knox or Sollecito;

(3) Guede was not involved in the murder but Knox and Sollecito were;

(4) None of Guede, Knox, or Sollecito were involved in the murder.

I think that the probability of (1) is roughly 90%; (2) is roughly 9+%; (3) is negligible; and (4) is negligible.

Make sense?

(I also think that the chances that Knox was involved but not Sollecito or vice versa are negligible)

continue this thread »

Comment author: bigjeff5 11 November 2011 02:18:28AM 1 point [-]

Can you show me where I did that? My recollection is I estimated roughly 99% for Guede's guilt.

I agree that it would not make sense to estimate 90% for Knox, Sollecito, and Guede to all be involved in the murder and 90% for Guede alone.

My apologies, I misread/misremembered your original assessment. I should have double checked before posting; you can ignore that whole portion of my post.

(1) When did Knox first become concerned about Kercher's absence?

(2) When did Sollecito and Knox first call the police and why?

These circumstances are enough to drive suspicion toward Knox and Sollecito, but without any sort of physical evidence to back up the suspicions they are insignificant. There are a lot of possible explanations for their behavior and the vast majority don't include murder.

(3) If it turns out that the ransacking of Romanelli's room was a staged burglary, do you agree that this is decent evidence against Knox?

If it is proven that it was staged by Knox/Sollecito, then absolutely. The inverse is also true, however: if Knox/Sollecito are innocent, then they didn't fake the break-in. The evidence that the break-in was staged is very weak, which is exactly what you expect to see if they are innocent.

This is the part, I think, that you are missing: the physical evidence (including reliable electronic evidence) is extremely strong evidence. It is "trumps everything" kind of strong. Slightly odd behavior is incredibly weak evidence. There is a huge amount of physical evidence in this case, and none of it points to Knox or Sollecito. The likelihood that they could be guilty of murder without leaving any evidence behind is incredibly small. Without evidence of any sort of link between Guide and Knox/Sollecito the complete lack of physical evidence of their involvement trumps the little bit of circumstantial evidence by a wide margin.

Comment author: brazil84 11 November 2011 02:51:35AM -2 points [-]

These circumstances are enough to drive suspicion toward Knox and Sollecito, but without any sort of physical evidence to back up the suspicions they are insignificant. There are a lot of possible explanations for their behavior and the vast majority don't include murder.

It seems you are unable to answer two questions which would have been pretty easy if you understood the case against Knox and Sollecito and were still satisfied of their innocence. To be sure, they are komponisto-disingenuous questions. But still, why not simply try to answer them anyway?

This is the part, I think, that you are missing: the physical evidence (including reliable electronic evidence) is extremely strong evidence. It is "trumps everything" kind of strong. Slightly odd behavior is incredibly weak evidence.

Again, it seems pretty clear to me that you do not understand the case against Knox and Sollecito, which is far more than "slightly odd behavior."

Without evidence of any sort of link between Guide and Knox/Sollecito

By the way, did you know that there was in fact evidence of such a link presented? I was surprised myself to learn about it.

continue this thread »

Comment author: TimS 10 November 2011 06:13:06PM 0 points [-]

What do you think are some of the best pieces of evidence against Knox and Sollecito?

Honestly, given what I know about the facts, the strongest evidence of guilt is that Knox and Sollecito were roommates of Knox.

Comment author: brazil84 10 November 2011 06:27:26PM -2 points [-]

Honestly, given what I know about the facts, the strongest evidence of guilt is that Knox and Sollecito were roommates of Knox.

Are you familiar with the case against Knox and Sollecito?

Comment author: TimS 10 November 2011 06:42:47PM 0 points [-]

I would say moderately familiar. But most of my knowledge is based on gwern's posts on the case. Are there significant facts not mentioned in the posts?

Comment author: komponisto 10 November 2011 06:59:10PM 0 points [-]

But most of my knowledge is based on gwern's posts on the case

FYI: gwern and I are not the same person.

continue this thread »

Comment author: brazil84 comment score below threshold [+] (40 children)

Comment author: brazil84 21 October 2011 04:14:43AM -2 points [-]

There's this thing, it's called 'logical fallacy'

Sure, and the fallacy does not automatically apply every time one poster comments on another poster's motivations. Note that wedrifid did not make any actual argument about Knox's guilt or innocence in his post; he did however offer his opinion that my conclusion on this issue was not sane.

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