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This is exactly my experience. I have never known what type the error I was talking about was... Imagine calling (for instance) type I groups those which are a

This is exactly my experience. I have never known what type the error I was talking about was... Imagine calling (for instance) type I groups those which are abelian and type II those which are not... And then not being a professional mathematician. So is xy=yx here? Mmmmhhh type I says yes or was it no?

twanvl 7y ago
Imagine mathematicians calling commutative groups abelian? How do you remember if xy=yx there?
- jerf 7y ago
  "Abelian" is at least a fresh new concept to hang your own associations off of, with no previous interference, and without interference from the similarly-named "Adelian" groups or something equally stupid. The problem isn't just that the term is something you've never heard before, but that "I" and "II" is not a very good concept to try to hang them off of. This is relevant to software engineering naming too: In general, you should not use naming schemes that imply properties that don't actually exist in your values. I and II have all sorts of properties that don't apply to the terms in question, most noticeably, they have an order. But, which is "first", false positives or false negatives? They don't have a natural order. Using numbers to name them just gets in the way. (Especially when there are perfectly serviceable words.) Math jargon isn't perfect by any means. But it does at least avoid naming things by sheer numbers most of the time, unless there isn't really a choice because it needs a few hundred names right now. (Similarly, pop quiz: In Kahneman's classification scheme, is System 1 the fast or the slow system? Odds are, even if you get that right, it's because the book title "Thinking, Fast and Slow" is something that stuck and it happen to be in order. It probably wasn't because you remember them by number.)
- thaumasiotes 7y ago
  > Imagine mathematicians calling commutative groups abelian? How do you remember if xy=yx there? Actually, even if you ignore jerf's response, this is different in an important way from the "Type I" / "Type II" terminology. Group in which the group operation is commutative: "Abelian group". Group with no guarantees except the group axioms: "group". The special one is marked and the non-special one is unmarked. In contrast, the designations "Type I" and "Type II" are parallel; it's not at all obvious which one is the default and which one deviates from the default.
laichzeit0 7y ago
I have the same problem with specificity and sensitivity. Always have to look up the damned terms even though I’ve used them countless of times.
- deleted 7y ago
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- ImaCake 7y ago
  They mean what they would mean in common english. Specificity because "how specific is the test? Does it measure the true positives correctly without getting a whole heap of false positives as well?" You might ask someone to be "more specific" about something so they aren't including irrelevant things in their discussion. Sensitivity because "how sensitive is the test? Does it detect the needle in the haystack you need to find? How many does it miss." In common english you might complain that your car brakes are too sensitive - they are too quick to register the pressure from your foot. Don't forget these are actually strict mathematical concepts. Hope this helps clarify :)
  - parekhnish 7y ago
    I think the issue people have with these names is that their English meanings (as you described) make sense when the positive class is not as prevalent as the negative class. If they are equally probable (or worse, if it's the opposite), then the English meanings quickly become out-of-context
  - ashfromconvert 7y ago
    Thank you for your clear explanation, indeed Specificity instead of Type I errors, and Senvisity for Type II errors, make a lot more sense!

twanvl 7y ago

Imagine mathematicians calling commutative groups abelian? How do you remember if xy=yx there?

jerf 7y ago
"Abelian" is at least a fresh new concept to hang your own associations off of, with no previous interference, and without interference from the similarly-named "Adelian" groups or something equally stupid. The problem isn't just that the term is something you've never heard before, but that "I" and "II" is not a very good concept to try to hang them off of. This is relevant to software engineering naming too: In general, you should not use naming schemes that imply properties that don't actually exist in your values. I and II have all sorts of properties that don't apply to the terms in question, most noticeably, they have an order. But, which is "first", false positives or false negatives? They don't have a natural order. Using numbers to name them just gets in the way. (Especially when there are perfectly serviceable words.) Math jargon isn't perfect by any means. But it does at least avoid naming things by sheer numbers most of the time, unless there isn't really a choice because it needs a few hundred names right now. (Similarly, pop quiz: In Kahneman's classification scheme, is System 1 the fast or the slow system? Odds are, even if you get that right, it's because the book title "Thinking, Fast and Slow" is something that stuck and it happen to be in order. It probably wasn't because you remember them by number.)
thaumasiotes 7y ago
> Imagine mathematicians calling commutative groups abelian? How do you remember if xy=yx there? Actually, even if you ignore jerf's response, this is different in an important way from the "Type I" / "Type II" terminology. Group in which the group operation is commutative: "Abelian group". Group with no guarantees except the group axioms: "group". The special one is marked and the non-special one is unmarked. In contrast, the designations "Type I" and "Type II" are parallel; it's not at all obvious which one is the default and which one deviates from the default.

laichzeit0 7y ago

I have the same problem with specificity and sensitivity. Always have to look up the damned terms even though I’ve used them countless of times.

deleted 7y ago
[deleted]
ImaCake 7y ago
They mean what they would mean in common english. Specificity because "how specific is the test? Does it measure the true positives correctly without getting a whole heap of false positives as well?" You might ask someone to be "more specific" about something so they aren't including irrelevant things in their discussion. Sensitivity because "how sensitive is the test? Does it detect the needle in the haystack you need to find? How many does it miss." In common english you might complain that your car brakes are too sensitive - they are too quick to register the pressure from your foot. Don't forget these are actually strict mathematical concepts. Hope this helps clarify :)
- parekhnish 7y ago
  I think the issue people have with these names is that their English meanings (as you described) make sense when the positive class is not as prevalent as the negative class. If they are equally probable (or worse, if it's the opposite), then the English meanings quickly become out-of-context
- ashfromconvert 7y ago
  Thank you for your clear explanation, indeed Specificity instead of Type I errors, and Senvisity for Type II errors, make a lot more sense!