3 ms·

> But why not use the abs function or operator rather than squaring and rooting? You can. It's called the mean absolute deviation. Which one you use depends on

> But why not use the abs function or operator rather than squaring and rooting? You can. It's called the mean absolute deviation. Which one you use depends on your application. If you just want to give a summary of how spread out the data is then either would work. Lots of people say that we should use the mean absolute deviation as the default rather than the standard deviation.

TeMPOraL 7y ago
And suddenly another small subarea of maths starts to make sense for me. Thank you, and thanks to everyone commenting in this subthread. I too have a problem with math tools passed down without any surrounding context - without telling why are we using this formula, instead of any other variant from the family of formulas that would satisfy the same goals. I'd have much easier time dealing with statistics in school if someone told me that a) deviation with ABS instead of root-square is also a thing, and b) we use the root-square one because it amplifies offsets from the mean.
- zorked 7y ago
  By the way, statistics as its own discipline is taught rather differently from the "here is a toolkit of magic tables and formulas and how to use it" method used when teaching it to non-statisticians. The magical bits actually make sense.
- dboreham 7y ago
  >I too have a problem with math tools passed down without any surrounding context Also one of my peeves. However over the years I've come to realize that in addition to teachers who omit the context, there is also a class of student that actively doesn't want to hear the context. I'm not sure exactly why this is, but I see it in my immediate family quite a bit. A sort of <cover ears, lalalala...too much detail> kind of thing perhaps due to difficulty taking on too much information?
Isinlor 7y ago
The mean absolute deviation should be always introduced to people before introducing standard deviation. When trying to figure out what the heck is the standard deviation I also stumbled upon the mean absolute deviation. Now, to me, the standard deviation is the mean absolute deviation. It's just a version that is more sensitive to outliers. Otherwise, I still don't feel like I intuitively (visually) understand the standard deviation. I feel like the standard deviation is a black box to basically everyone without statistics degree. It also bothers me that it is so widespread, because almost nobody know how to interpret this value. It seems to me like most scientists treat the standard deviation as a magical number that allows to compare spread between datasets and otherwise doesn't mean anything on it's own. I feel like a lot more insight could be gained from the mean absolute deviation. I'm also curious how are scientific insights affected by defaulting to something that is extra-sensitive to outliers. The effect can't be big per single research, but in collective?

TeMPOraL 7y ago

And suddenly another small subarea of maths starts to make sense for me. Thank you, and thanks to everyone commenting in this subthread. I too have a problem with math tools passed down without any surrounding context - without telling why are we using this formula, instead of any other variant from the family of formulas that would satisfy the same goals. I'd have much easier time dealing with statistics in school if someone told me that a) deviation with ABS instead of root-square is also a thing, and b) we use the root-square one because it amplifies offsets from the mean.

zorked 7y ago
By the way, statistics as its own discipline is taught rather differently from the "here is a toolkit of magic tables and formulas and how to use it" method used when teaching it to non-statisticians. The magical bits actually make sense.
dboreham 7y ago
>I too have a problem with math tools passed down without any surrounding context Also one of my peeves. However over the years I've come to realize that in addition to teachers who omit the context, there is also a class of student that actively doesn't want to hear the context. I'm not sure exactly why this is, but I see it in my immediate family quite a bit. A sort of <cover ears, lalalala...too much detail> kind of thing perhaps due to difficulty taking on too much information?

Isinlor 7y ago

The mean absolute deviation should be always introduced to people before introducing standard deviation. When trying to figure out what the heck is the standard deviation I also stumbled upon the mean absolute deviation. Now, to me, the standard deviation is the mean absolute deviation. It's just a version that is more sensitive to outliers. Otherwise, I still don't feel like I intuitively (visually) understand the standard deviation. I feel like the standard deviation is a black box to basically everyone without statistics degree. It also bothers me that it is so widespread, because almost nobody know how to interpret this value. It seems to me like most scientists treat the standard deviation as a magical number that allows to compare spread between datasets and otherwise doesn't mean anything on it's own. I feel like a lot more insight could be gained from the mean absolute deviation. I'm also curious how are scientific insights affected by defaulting to something that is extra-sensitive to outliers. The effect can't be big per single research, but in collective?