6 ms·

The Amanda Knox Test: How an Hour on the Internet Beats a Year in the Courtroom

35 points by rms 17y ago

ezy 17y ago
e.g. A bunch of people debate "rationality" using a few "priors" based on flimsy evidence from the internet. Just because you can use Bayesian nomenclature to snow others, doesn't make it rational. This whole thing hinges on the priors, and the author has given very weak evidence for them.
- rms 17y ago
  The "flimsy evidence from the internet" is the same or perhaps more complete than the courtroom evidence.
  - ezy 17y ago
    Is that actually true, or are you assuming that is true? The comments on the post relate further evidence that was missing from the analysis the poster provides. Why? Because the poster made a judgement call that it wasn't relevant. That alone makes this just so much blathering... sorry.
    - deleted 17y ago
      [deleted]
    - rms 17y ago
      I think the evidence on the internet firmly establishes that there is a substantial probability that Knox and Solecito are guilty of lying about the events of the evening but that does not come to close to establishing that they committed murder. There is a reasonable doubt. What evidence is missing from the internet that makes them guilty? I guess we will find out in a few months when the judge and jury issue their written explanation. Is anyone willing to state that they are certain Knox and Solecito are guilty of murder?
- frisco 17y ago
  The whole thing doesn't hinge on the priors: the priors should be rather easy to agree to (i.e., the observable rate at which the general population in Amanda Knox's relative bucket commit murders). The author's entire point is that all of the evidence presented against Ms Knox is irrelevant because the bar for it to be incriminating is way high given the evidence against Guede (and it doesn't meet that bar).
  - ezy 17y ago
    This doesn't make sense. For two reasons. (a) It isn't zero-sum. Guede was convicted -- he is guilty, he did it. What we are determining is whether he acted alone. (b) The priors are crap because they are weak, not because they are agreed upon. This is just a model, and it feels to me that the author is overfitting. The prior you mentioned as an example is so far away from the case at hand to be virtually useless.
    - frisco 17y ago
      So, you're right in that Guede being guilty doesn't imply that Knox isn't. But, the evidence against him affects how the evidence against Knox has to be handled: for example, the lack of physical evidence against Knox becomes a big deal when Guede leaves tons of it. Re: priors being far away: a prior is the probability of an event occurring before any evidence has been observed. Priors are always necessarily that far removed; those are the correct priors.
      - zaphar 17y ago
        How exactly does the evidence against Guede affect the regarding of evidence against Knox? Assuming that everyone involved (if it was multiple parties) were equally involved equally competent and hiding their involvement and left equal evidence of their involvement is just that an "assumption". It's not necessarily true and is in fact highly unlikely to be true. In the article actual physical evidence is dismissed because it's "small in quantity". The amount of blood is far less important than whose blood it is. You only need a little dna to prove contact. And you only need a little blood to prove prescence at the scene of an injury. It sounds to me like the jury was doing it's job and the article's author was just looking for a point to make.
- tel 17y ago
  Not quite. The author's point is that, at least according to released information and any unavoidable biases involved, the physical evidence strongly suggests Guede while hardly even slightly suggesting he had help. More strongly the author is trying to argue that its an easy fallacy to get drawn into psychological motives because we're "great" at modeling other people's thoughts. In light of this implicitly perceived strength we tend to ignore the real likelihood of the evidences. I don't know if it's something I agree about, however. I haven't personally reviewed the evidence and don't particularly put a lot of trust in any of the sources including the Less Wrong contributors. See also: the experimental portion of this essay http://lesswrong.com/lw/1j7/the_amanda_knox_test_how_an_hour_on_the_internet/ http://lesswrong.com/lw/1j7/the_amanda_knox_test_how_an_hour...
heyitsnick 17y ago
The media has truely outdone itself is mis-reporting this case, and sadly this article - surprisingly for one focused on rational thought - is no exception. There is a body of hard evidence, including forensic, such as (but not an exhaustive list): - 4 mixed DNA samples of the Knox and Kercher. Bloody footprints that match. Blood on the tap put Knox at the crime scene that evening or in the early morning. - A bloody bra in the washing machine - Attempts to frame an innocent man for the crime. - Repeated lying to authorities regarding her whereabouts. Still no fixed alibi. - Knox and Kercher's house was cleaned with bleach. - Sollecito's trainers were cleaned with bleach. A defect in the sole match a blood print on the scene. The decision went through going through 19 expert judges and 6 lay judges. Conviction was unanimous. Certainly, we can ignore some of the strange behaviour of the convicted (the phone calls, the lies, her past). But the case is much stronger than what this article makes out. This is an English translation of the judge's summary: http://www.zimbio.com/Amanda+Knox/articles/58/Understanding+Micheli+2+Judge+Micheli+Rejected http://www.zimbio.com/Amanda+Knox/articles/58/Understanding+... Other links: http://truejustice.org/ee/index.php?/tjmk/comments/how_the_media_should_approach_the_case_if_justice_is_to_be_done_and_seen_to/ http://truejustice.org/ee/index.php?/tjmk/comments/how_the_m... http://www.truejustice.org/ee/index.php?/tjmk/comments/why_defendants_mostly_dont_testify_those_devils_that_lurk_in_the_details/ http://www.truejustice.org/ee/index.php?/tjmk/comments/why_d... http://truejustice.org/ee/index.php?/tjmk/comments/highlights_of_the_testimony_on_6_february_and_7_february/ http://truejustice.org/ee/index.php?/tjmk/comments/highlight... http://www.timesonline.co.uk/tol/news/world/europe/article3629353.ece http://www.timesonline.co.uk/tol/news/world/europe/article36... http://www.guardian.co.uk/world/2009/feb/08/kercher-trial-knox http://www.guardian.co.uk/world/2009/feb/08/kercher-trial-kn... edit: I left out a few other key points to the prosecutions case: - Eye witness putting all 3 suspects together outside the cottage that night, and the night previous. - Knox and Sollecito standing outside the crime scene when the police arrived with mop and bucket. Rational thought takes anyone first to the conclusion that there was more than one killer. Guede left the scene soon after the murder (eye witness reports; evidence of cleaning, Guede's own statement). It is clear the crime scene was later returned to, and altered to cover evidence (faked break-in; footprints; removal of bra from the body). With all the additional evidence against Knox and Sollecito, physical and circumstantial, clear motive, and consitantly irrational behaviour, gives a very strong prosecution case. This article touches on little of these facts.
herdrick 17y ago
The point of the post on lesswrong.com is that since it's agreed that Guede murdered the victim, you have completely explained away the murder. So now you must start over, from scratch, as if the victim were still alive, and ask how likely it is that Knox and Sollecito killed somebody based on the other evidence: that both lied repeatedly to the police, that there was only one good fingerprint of hers within her own apartment, that she uses bleach to clean her apartment, and so on. Taking that evidence by itself - without any dead or missing person, mind you - would you even accuse them of anything more serious than obstructing the police? And yes, the priors - like the probability that a 20 year old female college student with no history of violence or mental disturbance of any kind would commit a murder - are certainly very relevant. That is one of the least violent categorizations of humans you can create. (In fact a more accurate prior would be even more miniscule: the probability that such a person would lead an elaborate team sex murder, an act so rare there is no term for it.) (However, there is some other evidence that is hard to deal with in this model, like the crime lab saying that there is Knox DNA on the bloody bra clasp of the victim. That evidence seems hopelessly entangled with the murder. How can this model be used to reason about it?) Anyway, all I know of the case is what other commenters here and the OP on lesswrong.com wrote, so my facts are suspect. I've just tried to explain what the OP is saying. Did I succeed?
- rms 17y ago
  I think you did, and it's important to say that the Less Wrong OP has just made one of many different cases for why reasonable doubt exists. This approach was not used at the trial because the defense argued the version of the truth that Knox and Solecito tried to create.
  - herdrick 17y ago
    Glad to hear it. The OP would say that his framework is the only rational one.
    - rms 17y ago
      Probably. If so, I'd like to hear how his idealized Bayesian system of justice works. The legal system doesn't work on Bayesian analysis. It has a probability system defined based on the meaning of English words... http://en.wikipedia.org/wiki/Burden_of_proof#Standards_for_detentions.2C_searches.2C_arrests_or_warrants http://en.wikipedia.org/wiki/Burden_of_proof#Standards_for_d...
citatus 17y ago
As computer people, scientists etc you should all be aware of the dangers of untrained outsiders who believe that they can not only understand a complex field with a minimum of logic, rationality and commonsense but understand it better than the trained professionals in that field. As a practicing lawyer, this analysis really sounds to me like the analysis of an intelligent climate skeptic or an intelligent arts graduate sounding forth on AI. Criminal justice systems are hard. They're right up their with the hardest things humanity has to deal with. They deal with ambiguous facts, necessarily inadequate rule systems and with intelligent human actors constantly trying to game the system - what's more the stakes are terrifyingly high, up to and including the life or death of the participants. Sure, errors tragically occur. But we should really pause before pronouncing --- based on Bayes, blogs and journalists --- that the cursory judgement of a non-profesional who wasn't in the court is superior to the considered judgement of judge and jury made in full cognisance of the likely outcome of conviction after listening to all the evidence including first hand witness testimony. And no, throwing in an offhand comment about how Occam's razor disproves God and therefore a little logic wielded with "courage and a certain kind of ruthlessness" enables superior thinkers to do better than the hidebound judge and jury (who were probably irrational Christians anyway) doesn't make the argument any more convincing.
- deleted 17y ago
  [deleted]
deleted 17y ago
[deleted]
antirez 17y ago
You can say everything about Italy, but not that our juridical system is broken in this way: it's much better than USA system in preventing innocent people from going to jail. There are three levels of giudice, and every level can only give you a penalty <= the previous one, and if there aren't many strong proofs it's likely you will not get marked as guilty. Also there is no such "popular jury", it's all made by professional people. We are mostly an irrelevant nation lately, but 2500 years of history of our juridical system are still in action.

35 points by rms 17y ago

ezy 17y ago

e.g. A bunch of people debate "rationality" using a few "priors" based on flimsy evidence from the internet. Just because you can use Bayesian nomenclature to snow others, doesn't make it rational. This whole thing hinges on the priors, and the author has given very weak evidence for them.

rms 17y ago
The "flimsy evidence from the internet" is the same or perhaps more complete than the courtroom evidence.
- ezy 17y ago
  Is that actually true, or are you assuming that is true? The comments on the post relate further evidence that was missing from the analysis the poster provides. Why? Because the poster made a judgement call that it wasn't relevant. That alone makes this just so much blathering... sorry.
  - deleted 17y ago
    [deleted]
  - rms 17y ago
    I think the evidence on the internet firmly establishes that there is a substantial probability that Knox and Solecito are guilty of lying about the events of the evening but that does not come to close to establishing that they committed murder. There is a reasonable doubt. What evidence is missing from the internet that makes them guilty? I guess we will find out in a few months when the judge and jury issue their written explanation. Is anyone willing to state that they are certain Knox and Solecito are guilty of murder?
frisco 17y ago
The whole thing doesn't hinge on the priors: the priors should be rather easy to agree to (i.e., the observable rate at which the general population in Amanda Knox's relative bucket commit murders). The author's entire point is that all of the evidence presented against Ms Knox is irrelevant because the bar for it to be incriminating is way high given the evidence against Guede (and it doesn't meet that bar).
- ezy 17y ago
  This doesn't make sense. For two reasons. (a) It isn't zero-sum. Guede was convicted -- he is guilty, he did it. What we are determining is whether he acted alone. (b) The priors are crap because they are weak, not because they are agreed upon. This is just a model, and it feels to me that the author is overfitting. The prior you mentioned as an example is so far away from the case at hand to be virtually useless.
  - frisco 17y ago
    So, you're right in that Guede being guilty doesn't imply that Knox isn't. But, the evidence against him affects how the evidence against Knox has to be handled: for example, the lack of physical evidence against Knox becomes a big deal when Guede leaves tons of it. Re: priors being far away: a prior is the probability of an event occurring before any evidence has been observed. Priors are always necessarily that far removed; those are the correct priors.
    - zaphar 17y ago
      How exactly does the evidence against Guede affect the regarding of evidence against Knox? Assuming that everyone involved (if it was multiple parties) were equally involved equally competent and hiding their involvement and left equal evidence of their involvement is just that an "assumption". It's not necessarily true and is in fact highly unlikely to be true. In the article actual physical evidence is dismissed because it's "small in quantity". The amount of blood is far less important than whose blood it is. You only need a little dna to prove contact. And you only need a little blood to prove prescence at the scene of an injury. It sounds to me like the jury was doing it's job and the article's author was just looking for a point to make.
tel 17y ago
Not quite. The author's point is that, at least according to released information and any unavoidable biases involved, the physical evidence strongly suggests Guede while hardly even slightly suggesting he had help. More strongly the author is trying to argue that its an easy fallacy to get drawn into psychological motives because we're "great" at modeling other people's thoughts. In light of this implicitly perceived strength we tend to ignore the real likelihood of the evidences. I don't know if it's something I agree about, however. I haven't personally reviewed the evidence and don't particularly put a lot of trust in any of the sources including the Less Wrong contributors. See also: the experimental portion of this essay http://lesswrong.com/lw/1j7/the_amanda_knox_test_how_an_hour_on_the_internet/ http://lesswrong.com/lw/1j7/the_amanda_knox_test_how_an_hour...

heyitsnick 17y ago

The media has truely outdone itself is mis-reporting this case, and sadly this article - surprisingly for one focused on rational thought - is no exception. There is a body of hard evidence, including forensic, such as (but not an exhaustive list): - 4 mixed DNA samples of the Knox and Kercher. Bloody footprints that match. Blood on the tap put Knox at the crime scene that evening or in the early morning. - A bloody bra in the washing machine - Attempts to frame an innocent man for the crime. - Repeated lying to authorities regarding her whereabouts. Still no fixed alibi. - Knox and Kercher's house was cleaned with bleach. - Sollecito's trainers were cleaned with bleach. A defect in the sole match a blood print on the scene. The decision went through going through 19 expert judges and 6 lay judges. Conviction was unanimous. Certainly, we can ignore some of the strange behaviour of the convicted (the phone calls, the lies, her past). But the case is much stronger than what this article makes out. This is an English translation of the judge's summary: http://www.zimbio.com/Amanda+Knox/articles/58/Understanding+Micheli+2+Judge+Micheli+Rejected http://www.zimbio.com/Amanda+Knox/articles/58/Understanding+... Other links: http://truejustice.org/ee/index.php?/tjmk/comments/how_the_media_should_approach_the_case_if_justice_is_to_be_done_and_seen_to/ http://truejustice.org/ee/index.php?/tjmk/comments/how_the_m... http://www.truejustice.org/ee/index.php?/tjmk/comments/why_defendants_mostly_dont_testify_those_devils_that_lurk_in_the_details/ http://www.truejustice.org/ee/index.php?/tjmk/comments/why_d... http://truejustice.org/ee/index.php?/tjmk/comments/highlights_of_the_testimony_on_6_february_and_7_february/ http://truejustice.org/ee/index.php?/tjmk/comments/highlight... http://www.timesonline.co.uk/tol/news/world/europe/article3629353.ece http://www.timesonline.co.uk/tol/news/world/europe/article36... http://www.guardian.co.uk/world/2009/feb/08/kercher-trial-knox http://www.guardian.co.uk/world/2009/feb/08/kercher-trial-kn... edit: I left out a few other key points to the prosecutions case: - Eye witness putting all 3 suspects together outside the cottage that night, and the night previous. - Knox and Sollecito standing outside the crime scene when the police arrived with mop and bucket. Rational thought takes anyone first to the conclusion that there was more than one killer. Guede left the scene soon after the murder (eye witness reports; evidence of cleaning, Guede's own statement). It is clear the crime scene was later returned to, and altered to cover evidence (faked break-in; footprints; removal of bra from the body). With all the additional evidence against Knox and Sollecito, physical and circumstantial, clear motive, and consitantly irrational behaviour, gives a very strong prosecution case. This article touches on little of these facts.

herdrick 17y ago

The point of the post on lesswrong.com is that since it's agreed that Guede murdered the victim, you have completely explained away the murder. So now you must start over, from scratch, as if the victim were still alive, and ask how likely it is that Knox and Sollecito killed somebody based on the other evidence: that both lied repeatedly to the police, that there was only one good fingerprint of hers within her own apartment, that she uses bleach to clean her apartment, and so on. Taking that evidence by itself - without any dead or missing person, mind you - would you even accuse them of anything more serious than obstructing the police? And yes, the priors - like the probability that a 20 year old female college student with no history of violence or mental disturbance of any kind would commit a murder - are certainly very relevant. That is one of the least violent categorizations of humans you can create. (In fact a more accurate prior would be even more miniscule: the probability that such a person would lead an elaborate team sex murder, an act so rare there is no term for it.) (However, there is some other evidence that is hard to deal with in this model, like the crime lab saying that there is Knox DNA on the bloody bra clasp of the victim. That evidence seems hopelessly entangled with the murder. How can this model be used to reason about it?) Anyway, all I know of the case is what other commenters here and the OP on lesswrong.com wrote, so my facts are suspect. I've just tried to explain what the OP is saying. Did I succeed?

rms 17y ago
I think you did, and it's important to say that the Less Wrong OP has just made one of many different cases for why reasonable doubt exists. This approach was not used at the trial because the defense argued the version of the truth that Knox and Solecito tried to create.
- herdrick 17y ago
  Glad to hear it. The OP would say that his framework is the only rational one.
  - rms 17y ago
    Probably. If so, I'd like to hear how his idealized Bayesian system of justice works. The legal system doesn't work on Bayesian analysis. It has a probability system defined based on the meaning of English words... http://en.wikipedia.org/wiki/Burden_of_proof#Standards_for_detentions.2C_searches.2C_arrests_or_warrants http://en.wikipedia.org/wiki/Burden_of_proof#Standards_for_d...

citatus 17y ago

As computer people, scientists etc you should all be aware of the dangers of untrained outsiders who believe that they can not only understand a complex field with a minimum of logic, rationality and commonsense but understand it better than the trained professionals in that field. As a practicing lawyer, this analysis really sounds to me like the analysis of an intelligent climate skeptic or an intelligent arts graduate sounding forth on AI. Criminal justice systems are hard. They're right up their with the hardest things humanity has to deal with. They deal with ambiguous facts, necessarily inadequate rule systems and with intelligent human actors constantly trying to game the system - what's more the stakes are terrifyingly high, up to and including the life or death of the participants. Sure, errors tragically occur. But we should really pause before pronouncing --- based on Bayes, blogs and journalists --- that the cursory judgement of a non-profesional who wasn't in the court is superior to the considered judgement of judge and jury made in full cognisance of the likely outcome of conviction after listening to all the evidence including first hand witness testimony. And no, throwing in an offhand comment about how Occam's razor disproves God and therefore a little logic wielded with "courage and a certain kind of ruthlessness" enables superior thinkers to do better than the hidebound judge and jury (who were probably irrational Christians anyway) doesn't make the argument any more convincing.

deleted 17y ago
[deleted]

deleted 17y ago

[deleted]

antirez 17y ago

You can say everything about Italy, but not that our juridical system is broken in this way: it's much better than USA system in preventing innocent people from going to jail. There are three levels of giudice, and every level can only give you a penalty <= the previous one, and if there aren't many strong proofs it's likely you will not get marked as guilty. Also there is no such "popular jury", it's all made by professional people. We are mostly an irrelevant nation lately, but 2500 years of history of our juridical system are still in action.