Use “The Boy Who Cried Wolf” as a mnemonic. His first error is type 1 (claiming a wolf as present when there wasn’t one). His second error is type 2 (people don’t notice an existing wolf).
To fight back against terrible terminology from the other side (i.e., producing rather than consuming) I suggest a commitment to refuse to say “Type I error” or “Type II error” and always say “false positive” or “false negative” instead.
I find “false positive” and “false negative” also a bit confusing, albeit less so than “type I” and “type II” errors. Perhaps because of a programming background, I usually interpret ‘false’ and ‘negative’ (and ‘0’) as the same thing. So is a ‘false positive’ something that is false but is mistaken as positive, or something that is positive (true), but that is mistaken as false (negative)? In other words, does ‘false’ apply to the postiveness (it is actually negative, but classified as positive), to being classified as positive (it is actually positive, but classified as positive)?
Perhaps we should call false positives “spurious” and false negatives “missed”.
Huh. That never occurred to me (even though I spend a lot of my days writing code too).
In case you’re expressing actual uncertainty rather than merely what your brain gets confused about, the answer is that a false positive is something that falsely looks positive. Perhaps the best way to put it is different, though: a false positive is a positive result of your test (so it actually is a positive) that doesn’t match the underlying reality. Like a “false alarm”.
Introspecting, the way I remember this is that 1 is a simple number, and type 1 errors are errors that you make by being stupid in a simple way, namely by being gullible. 2 is a more sophisticated number, and type 2 errors are ones you make by being too skeptical, which is a more sophisticated type of stupidity. I do most simple memorization (e.g. memorizing differentiation rules) with this strategy of “rationalizing why the answer makes sense”. I think your method is probably better for most people, though.
http://mindhacks.com/2015/11/16/no-more-type-iii-error-confusion/#comments
Use “The Boy Who Cried Wolf” as a mnemonic. His first error is type 1 (claiming a wolf as present when there wasn’t one). His second error is type 2 (people don’t notice an existing wolf).
Nice.
To fight back against terrible terminology from the other side (i.e., producing rather than consuming) I suggest a commitment to refuse to say “Type I error” or “Type II error” and always say “false positive” or “false negative” instead.
I find “false positive” and “false negative” also a bit confusing, albeit less so than “type I” and “type II” errors. Perhaps because of a programming background, I usually interpret ‘false’ and ‘negative’ (and ‘0’) as the same thing. So is a ‘false positive’ something that is false but is mistaken as positive, or something that is positive (true), but that is mistaken as false (negative)? In other words, does ‘false’ apply to the postiveness (it is actually negative, but classified as positive), to being classified as positive (it is actually positive, but classified as positive)?
Perhaps we should call false positives “spurious” and false negatives “missed”.
Huh. That never occurred to me (even though I spend a lot of my days writing code too).
In case you’re expressing actual uncertainty rather than merely what your brain gets confused about, the answer is that a false positive is something that falsely looks positive. Perhaps the best way to put it is different, though: a false positive is a positive result of your test (so it actually is a positive) that doesn’t match the underlying reality. Like a “false alarm”.
Now that I know which is which, this will be very slightly harder for me than it used to be.
Introspecting, the way I remember this is that 1 is a simple number, and type 1 errors are errors that you make by being stupid in a simple way, namely by being gullible. 2 is a more sophisticated number, and type 2 errors are ones you make by being too skeptical, which is a more sophisticated type of stupidity. I do most simple memorization (e.g. memorizing differentiation rules) with this strategy of “rationalizing why the answer makes sense”. I think your method is probably better for most people, though.
Nice!
Ha, I wasn’t even aware of this. Really nice, thanks.