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> civilian demining which demands a 99% clearance rate. Is that an actual official classification? It seems a bit low. "There were 1000 mines here, and we fo

by Deestan 14y ago

> civilian demining which demands a 99% clearance rate. Is that an actual official classification? It seems a bit low. "There were 1000 mines here, and we found 990 of them. Good enough, I say. Move in, and bring your kids!"

_djo_ 14y ago
The actual figure is 99.6%.[0] That's the statistical confidence level for clearance required of contractors and to declare an area safe, because it's impossible to prove beyond any doubt that there is no longer a single mine left in an area. Demining teams still aim for 100% though. For instance, Mechem's sniffer dogs have displayed a 90% success rate on target filters, so statistically having three dogs per team perform cross-checking paths on the field should produce the 99.6% confidence level for the type of mines the dogs can detect. [0]http://www.un.org/Depts/dha/mct/rptwg2.htm http://www.un.org/Depts/dha/mct/rptwg2.htm
- novaleaf 14y ago
  mad props to you for finding this data and posting it
- gabemart 14y ago
  >For instance, Mechem's sniffer dogs have displayed a 90% success rate on target filters, so statistically having three dogs per team perform cross-checking paths on the field should produce the 99.6% confidence level for the type of mines the dogs can detect. I know nothing at all about this area, but presumably this only works if the 10% failure rate is random rather than based on some quality of the undetected mines?
  - T-hawk 14y ago
    More generally, that the chance of each dog X failing to detect each mine Y is independent. If it is independent, then you get the (1-P)^3 chance of failure, meaning 0.1% for all three failures if each dog has a 90% chance of succeeding. But of course that isn't true in reality. There will be properties of the mines (burial depth, ground cover, degree of leakage of sniffable explosive material) that affect its chance of being found by all dogs searching for a mine. If you wanted the parent poster's statistical chance, you'd want three 90% ways of detecting mines that are truly independent. Perhaps a dog, and infrared imaging sensitive enough to detect the explosive material (I have no idea if that's possible), and this article's mechanism.
    - _djo_ 14y ago
      Correct, that's why in real world scenarios companies like Mechem will use a number of techniques. The link I posted earlier makes it clear that the UN considers a combination of techniques necessary to meet the required standard.

by Deestan 14y ago

_djo_ 14y ago

The actual figure is 99.6%.[0] That's the statistical confidence level for clearance required of contractors and to declare an area safe, because it's impossible to prove beyond any doubt that there is no longer a single mine left in an area. Demining teams still aim for 100% though. For instance, Mechem's sniffer dogs have displayed a 90% success rate on target filters, so statistically having three dogs per team perform cross-checking paths on the field should produce the 99.6% confidence level for the type of mines the dogs can detect. [0]http://www.un.org/Depts/dha/mct/rptwg2.htm http://www.un.org/Depts/dha/mct/rptwg2.htm

novaleaf 14y ago
mad props to you for finding this data and posting it
gabemart 14y ago
>For instance, Mechem's sniffer dogs have displayed a 90% success rate on target filters, so statistically having three dogs per team perform cross-checking paths on the field should produce the 99.6% confidence level for the type of mines the dogs can detect. I know nothing at all about this area, but presumably this only works if the 10% failure rate is random rather than based on some quality of the undetected mines?
- T-hawk 14y ago
  More generally, that the chance of each dog X failing to detect each mine Y is independent. If it is independent, then you get the (1-P)^3 chance of failure, meaning 0.1% for all three failures if each dog has a 90% chance of succeeding. But of course that isn't true in reality. There will be properties of the mines (burial depth, ground cover, degree of leakage of sniffable explosive material) that affect its chance of being found by all dogs searching for a mine. If you wanted the parent poster's statistical chance, you'd want three 90% ways of detecting mines that are truly independent. Perhaps a dog, and infrared imaging sensitive enough to detect the explosive material (I have no idea if that's possible), and this article's mechanism.
  - _djo_ 14y ago
    Correct, that's why in real world scenarios companies like Mechem will use a number of techniques. The link I posted earlier makes it clear that the UN considers a combination of techniques necessary to meet the required standard.