3 ms·
The system has an eighty-one percent classification accuracy in a laboratory test setting That sounds pretty good -- "It catches 81% of the bad guys". It so
by panarky 12y ago
The system has an eighty-one percent classification accuracy
in a laboratory test setting
That sounds pretty good -- "It catches 81% of the bad guys".
It sounds good until you realize that bad guys are an infinitesimal portion of the population.
If bad guys are 1 in 1,000 or 1 in 100,000, virtually all of the people implicated by the system will be innocent.
- JadeNB 12y agoSpecifically, since the numbers are pretty unbelieveable if you haven't seen such arguments before: if the bad guys are as numerous as 1 in 1000, then the number of false positives will be 999*19% > 189 in 1000. That is, if you are identified as a bad guy, then the odds are worse than 1 in 190 (just over 0.5%) that you are one.