Variance? Standard Deviation? Eureka!
Saturday, February 2nd, 2013 06:52 pm![[personal profile]](https://www.dreamwidth.org/img/silk/identity/user.png){kind=small}
afunaI've been sucked into coursera, and I've started a couple math-based classes.
The last time I tried this, I stopped a few weeks in because I tried too many hard classes at the same time, and couldn't work them into my schedule. This time I'm ramping up more slowly: intermediate algebra (to brush up my skills), pre-calculus (same, but at a more accelerated pace), and data analysis.
I find statistics a challenge. I get the basic underlying concepts in an abstract manner, but find it really difficult when it comes to actually applying them. Which points to my not really understanding the basic underlying concepts, heh.
Just had my first eureka moment: I can happily parrot back that SD = square root of variance, but I never got why it mattered which one you used. And just two sentences cleared up years' worth of confusion:
"Variance is expressed in (units of x) squared. Standard deviation is often preferred because it is expressed in units of x"
GIGANTIC LIGHTBULB.
The last time I tried this, I stopped a few weeks in because I tried too many hard classes at the same time, and couldn't work them into my schedule. This time I'm ramping up more slowly: intermediate algebra (to brush up my skills), pre-calculus (same, but at a more accelerated pace), and data analysis.
I find statistics a challenge. I get the basic underlying concepts in an abstract manner, but find it really difficult when it comes to actually applying them. Which points to my not really understanding the basic underlying concepts, heh.
Just had my first eureka moment: I can happily parrot back that SD = square root of variance, but I never got why it mattered which one you used. And just two sentences cleared up years' worth of confusion:
"Variance is expressed in (units of x) squared. Standard deviation is often preferred because it is expressed in units of x"
GIGANTIC LIGHTBULB.
