In a discussion about the latest MRG test I found an interesting statement from IBK that I want to discuss separately to avoid hooking the other thread: I fully agree with that AMTSO principle. But it contains a big variable: "measured in a balanced way" I think the actual question is: How important is a false positive in relation to a non detected malware sample? Can there be ANY fair relation stated in numbers of a test result at all? There are arguments against: Only one missed malware sample can destroy the user's data completely. Do you think that an infected user would set the importance of a wrongly flagged good file the same as the virus which destroyed the data? Usually a false positive in quarantine can be easily restored once the detection is fixed (if it's not an essential system file of course). What's a balanced way between non detected and wrong detected? Is it 1:1, 1:10, 1:100 or 1:1000? Who defines that relation for a trusted and valuable antivirus comparative?