2 ms·

75% of homicide perpetrators identified correctly (15/20) + 82% of non-homicide perpetrators identified correctly (111/135) is a total classification accuracy o

by mewse 12y ago

75% of homicide perpetrators identified correctly (15/20) + 82% of non-homicide perpetrators identified correctly (111/135) is a total classification accuracy of 81% (126/155) for the procedure. But if we just assume that everyone is in the non-homicide group (which is what "innocent until proven guilty" has us do anyway), then that gives us a total classification accuracy of (135/155) 85% for the same sample set. That is, "innocent until proven guilty" is notably more accurate than the system which is being proposed here, and infinitely less likely to deliver a false positive result.

anigbrowl 12y ago
It can't be infinitely less likely to produce a false result or we'd never have miscarriages of justice. Current research estimates the rate of false positives in capital crimes (almost all of which are homicides) at 4.1%. http://www.pnas.org/content/early/2014/04/23/1306417111.full.pdf http://www.pnas.org/content/early/2014/04/23/1306417111.full... But the point here is that chance is only 50%, so if we have a mechanical system that's within shouting distance of matching our extremely elaborate and very expensive trial system then that's noteworthy. 81% is not far away from 87%; what happens when the machine learning system can repeatably identify homicidal behavior with greater accuracy than our criminal justice system? Overall accuracy is highly significant because it will create a lot of pressure to identify murderers in the interests of public safety. Of course we shouldn't rely on such a system because of the risk of false positives, but you'll see attempts to bring it into evidence in more and more cases. If/when such a system starts to outperform the existing on in terms of having a lower number of false positives, then every innocent defendant is going to demand it and every guilty defendant (in the legal sense) will cite it as a mitigating circumstance.

by mewse 12y ago

anigbrowl 12y ago

It can't be infinitely less likely to produce a false result or we'd never have miscarriages of justice. Current research estimates the rate of false positives in capital crimes (almost all of which are homicides) at 4.1%. http://www.pnas.org/content/early/2014/04/23/1306417111.full.pdf http://www.pnas.org/content/early/2014/04/23/1306417111.full... But the point here is that chance is only 50%, so if we have a mechanical system that's within shouting distance of matching our extremely elaborate and very expensive trial system then that's noteworthy. 81% is not far away from 87%; what happens when the machine learning system can repeatably identify homicidal behavior with greater accuracy than our criminal justice system? Overall accuracy is highly significant because it will create a lot of pressure to identify murderers in the interests of public safety. Of course we shouldn't rely on such a system because of the risk of false positives, but you'll see attempts to bring it into evidence in more and more cases. If/when such a system starts to outperform the existing on in terms of having a lower number of false positives, then every innocent defendant is going to demand it and every guilty defendant (in the legal sense) will cite it as a mitigating circumstance.