Are you saying there is no circumstantial evidence which suggests involvement of Knox and Sollecito?
No. The claim is that this evidence is weaker than the evidence against Guede by a factor of millions, and therefore deserves essentially zero brain time. See the “Epistemic Ruthlessness” section of the post, and the wiki entry “Amount of Evidence”.
The claim is that this evidence is weaker than the evidence against Guede by a factor of millions, and therefore deserves essentially zero brain time.
No, the evidence is weaker than it would need to be to overcome the prior improbability of “a rape known to have been committed by a random burglar in a flat was a product of conspiracy with a woman who lived there”, plus the absence of Knox DNA is very strong evidence against her presence. The degree of the evidence against Guede has nothing to do with the bar—the bar is set by the prior improbability, not by the strength of evidence that Guede happened to leave behind himself.
The claim is that this evidence is weaker than the evidence against Guede by a >factor of millions and therefore deserves essentially zero brain time.
It seems to me that (1) Guede murdered Kircher; and (2) Knox and Sollecito were involved in the murder, are not mutually exclusive hypotheses.
So the fact that there is an extremely strong case against Guede does not necessarily mean that the case against Knox and Sollecito is weak or extremely weak.
So the fact that there is an extremely strong case against Guede does not necessarily mean that the case against Knox and Sollecito is weak or extremely weak.
Indeed not; if we had 30 bits of anti-Knox evidence, the case against Knox would be strong too.
The case against Knox and Sollecito is weak because it is weak, not because the case against Guede is strong.
The case against Knox and Sollecito is weak because it is weak, not because the case against Guede is strong.
That’s why I keep on saying not to compare the amount of evidence against Guede to the case against Knox. It’s not a comparison operation. It doesn’t set a bar. It doesn’t set a standard. Now, the fact that Guede left a lot of DNA means it’s implausible that Knox cleaned up only her DNA and not Guede’s, but that’s a whole separate issue. And the fact that we know Guede did it means that there’s no unexplained murder around for Knox to be convicted of. But under other circumstances, it would be very easy to have a murder that was in fact committed by two people, one of whom left very strong evidence against herself, and one of whom left less strong but still conviction-worthy evidence against herself. It’s just not a relative operation.
Okay, I agree that ideal rational agents with unlimited computing resources shouldn’t “care” about the relative strength of evidence; all they have to do is perform the appropriate computation, and the result will come out to whatever it should be. But I’ve already conceded that “follow the strong signal” is a heuristic for human use, in order to get results that, in reality, better approximate what an ideal rational agent would come up with than the methods that are already programmed into us.
The situation we’re in is the following: we’re investigators on a budget, trying to figure out how to allocate our limited resources among various paths through hypothesis space. Let’s say there are two particular paths we’re considering, and at the entrance to each of them is a loudspeaker with a voice saying “FOLLOW THIS TRAIL”. Except that one of the voices is twice as loud as the other. Now, am I completely crazy, or is it not an epistemically reasonable thing to do to do something like allocate twice the investigative resources to following the signal that is twice as strong? How else should we divide it up?
I don’t think I need to remind you that reality is consistent: if Knox was really involved in a conspiracy with Guede, then the Knox trail will meet up with the Guede trail, in which case we’re not losing anything by devoting the lion’s share of our resources to starting along the Guede trail rather than the Knox trail.
The problem is that finding Guede’s semen inside Meredith is not evidence against the hypothesis “Guede and Knox murdered Meredith”. Guede’s already been caught, too. So now the question is whether to devote any of our remaining attention to trying to catch Knox, and the insufficient/disconfirmatory evidence for this fails to surpass the prior implausibility of the conspiracy hypothesis—it has nothing to do with how hard Guede was caught.
I’ve read elsewhere this was a manual rape—still leaves DNA inside but not necc. semen.
Manual rape? I’m not familiar with that term and a meaning fitting those criteria (DNA but not semen) isn’t obvious. I can only assume that ‘manual’ refers to, well, the last part of it. I wouldn’t have expected that kind of rape if murder was going to be on the cards and I would also expect semen around somewhere, showing up with luminol. So perhaps something else is meant.
Mainly because (1) there is evidence of alteration/staging; and (2) Knox and Sollecito are still unable to give accounts of the evening (and next morning) which are reasonably coherent and consistent.
I just want to say thanks for your posts, I have found them very interesting.
If the trial has been corrupted then one has to ask why the judge(s) involved would collude in such high profile corruption—that in itself seems unlikely unless there is an unsopken intention to reverse the verdict at appeal, having given the US ‘a dose of it’s own’. But that seems far fetched. Corruption happens for a reason and those reasons are also traceable.
Your argument that conviction was secured on the basis of a fanciful explanation but not without reason is persuasive. I too am of the opinion that things went on but I’m not sure that makes A and R as evil as they are portrayed or even guitly of murder.
But mainly, your posts are valuable because, without being able to argue the case mathematically, something clearly is wrong with this Bayesian worldview because it is not explaining life, and if Bayesian rationality is the key to ‘knowing’, as we are led to believe, then I would not be left feeling that many posts that adhere strictly to Bayesian reasoning are somehow missing the point. And I don’t think that is because I am an evolutionary throw-back, I think it is because I have a good sense of things not sounding right—I have that feeling with the Knox trial and with this blog. Ciao
or it could be that Knox and Sollicitos’ behaviours were so irrational that it is harder to fathom what the evidence means:
they both retracted statements
Italy’s legal system has been praised as well as criticised
the footprint on the bath mat paradox
the picture on S’s blog
K’s rape story
the verdict is for ‘involvement’ not physical action
capacity to be irrational induced by drugs, hormones, a generational obssession with the supernatural, and the perennial boredom of the over-educated bourgeoisie
I reckon that whatever happened that night, K/S got so close to the boundary between fanatsy and reality that they couldn’t risk admitting whatever folly they had been up to.
I think what is on trial is culture. I count at least 8.
No. The claim is that this evidence is weaker than the evidence against Guede by a factor of millions, and therefore deserves essentially zero brain time. See the “Epistemic Ruthlessness” section of the post, and the wiki entry “Amount of Evidence”.
No, the evidence is weaker than it would need to be to overcome the prior improbability of “a rape known to have been committed by a random burglar in a flat was a product of conspiracy with a woman who lived there”, plus the absence of Knox DNA is very strong evidence against her presence. The degree of the evidence against Guede has nothing to do with the bar—the bar is set by the prior improbability, not by the strength of evidence that Guede happened to leave behind himself.
It seems to me that (1) Guede murdered Kircher; and (2) Knox and Sollecito were involved in the murder, are not mutually exclusive hypotheses.
So the fact that there is an extremely strong case against Guede does not necessarily mean that the case against Knox and Sollecito is weak or extremely weak.
Indeed not; if we had 30 bits of anti-Knox evidence, the case against Knox would be strong too.
The case against Knox and Sollecito is weak because it is weak, not because the case against Guede is strong.
That’s why I keep on saying not to compare the amount of evidence against Guede to the case against Knox. It’s not a comparison operation. It doesn’t set a bar. It doesn’t set a standard. Now, the fact that Guede left a lot of DNA means it’s implausible that Knox cleaned up only her DNA and not Guede’s, but that’s a whole separate issue. And the fact that we know Guede did it means that there’s no unexplained murder around for Knox to be convicted of. But under other circumstances, it would be very easy to have a murder that was in fact committed by two people, one of whom left very strong evidence against herself, and one of whom left less strong but still conviction-worthy evidence against herself. It’s just not a relative operation.
Okay, I agree that ideal rational agents with unlimited computing resources shouldn’t “care” about the relative strength of evidence; all they have to do is perform the appropriate computation, and the result will come out to whatever it should be. But I’ve already conceded that “follow the strong signal” is a heuristic for human use, in order to get results that, in reality, better approximate what an ideal rational agent would come up with than the methods that are already programmed into us.
The situation we’re in is the following: we’re investigators on a budget, trying to figure out how to allocate our limited resources among various paths through hypothesis space. Let’s say there are two particular paths we’re considering, and at the entrance to each of them is a loudspeaker with a voice saying “FOLLOW THIS TRAIL”. Except that one of the voices is twice as loud as the other. Now, am I completely crazy, or is it not an epistemically reasonable thing to do to do something like allocate twice the investigative resources to following the signal that is twice as strong? How else should we divide it up?
I don’t think I need to remind you that reality is consistent: if Knox was really involved in a conspiracy with Guede, then the Knox trail will meet up with the Guede trail, in which case we’re not losing anything by devoting the lion’s share of our resources to starting along the Guede trail rather than the Knox trail.
What, if anything, am I missing here?
The problem is that finding Guede’s semen inside Meredith is not evidence against the hypothesis “Guede and Knox murdered Meredith”. Guede’s already been caught, too. So now the question is whether to devote any of our remaining attention to trying to catch Knox, and the insufficient/disconfirmatory evidence for this fails to surpass the prior implausibility of the conspiracy hypothesis—it has nothing to do with how hard Guede was caught.
Are you sure semen was found? I’ve read elsewhere this was a manual rape—still leaves DNA inside but not necc. semen.
Nope, not sure offhand.
Manual rape? I’m not familiar with that term and a meaning fitting those criteria (DNA but not semen) isn’t obvious. I can only assume that ‘manual’ refers to, well, the last part of it. I wouldn’t have expected that kind of rape if murder was going to be on the cards and I would also expect semen around somewhere, showing up with luminol. So perhaps something else is meant.
One meaning of ‘manual’ is ‘of or relating to the hands’. I’m guessing that’s what’s meant here.
I agree with this, except of course that I am reasonably confident Knox and Sollecito were involved in the murder.
And that would be because...?
(The fundamental question of rationality: why do you believe what you believe?)
Mainly because (1) there is evidence of alteration/staging; and (2) Knox and Sollecito are still unable to give accounts of the evening (and next morning) which are reasonably coherent and consistent.
How many total bits of evidence against Knox and Sollecito do you think these things are worth?
I’m not sure . . . I’m ignorant of the evaluation of evidence in terms of “bits.” Is there some link you can give me?
http://wiki.lesswrong.com/wiki/Bayes_theorem
http://causalityrelay.wordpress.com/2008/06/23/odds-and-intuitive-bayes/
http://www.overcomingbias.com/2009/02/share-likelihood-ratios-not-posterior-beliefs.html
http://en.wikipedia.org/wiki/Bayes_factor
Yes.
If my math is correct, I would say somewhere between 3 and 4 bits.
I just want to say thanks for your posts, I have found them very interesting.
If the trial has been corrupted then one has to ask why the judge(s) involved would collude in such high profile corruption—that in itself seems unlikely unless there is an unsopken intention to reverse the verdict at appeal, having given the US ‘a dose of it’s own’. But that seems far fetched. Corruption happens for a reason and those reasons are also traceable.
Your argument that conviction was secured on the basis of a fanciful explanation but not without reason is persuasive. I too am of the opinion that things went on but I’m not sure that makes A and R as evil as they are portrayed or even guitly of murder.
But mainly, your posts are valuable because, without being able to argue the case mathematically, something clearly is wrong with this Bayesian worldview because it is not explaining life, and if Bayesian rationality is the key to ‘knowing’, as we are led to believe, then I would not be left feeling that many posts that adhere strictly to Bayesian reasoning are somehow missing the point. And I don’t think that is because I am an evolutionary throw-back, I think it is because I have a good sense of things not sounding right—I have that feeling with the Knox trial and with this blog. Ciao
or it could be that Knox and Sollicitos’ behaviours were so irrational that it is harder to fathom what the evidence means:
they both retracted statements
Italy’s legal system has been praised as well as criticised
the footprint on the bath mat paradox
the picture on S’s blog
K’s rape story
the verdict is for ‘involvement’ not physical action
capacity to be irrational induced by drugs, hormones, a generational obssession with the supernatural, and the perennial boredom of the over-educated bourgeoisie
I reckon that whatever happened that night, K/S got so close to the boundary between fanatsy and reality that they couldn’t risk admitting whatever folly they had been up to.
I think what is on trial is culture. I count at least 8.