

I have just had to explain to someone what standard deviation is.
This person claims to have an ALevel in maths but was never taught it.
I don't disbelieve them, I am just amazed that Stats are not taught as part of the ALevel syllabus any more.
A sign you are getting old is when you are amazed at how little kids learn in school.

I will never again mention that I was the poster of the One Millionth Lounge Post, nor that it was complete drivel. Dalek Dave
CCC Link[ ^]





I took Statistics in college and I still don't really understand what standard deviation is... I can do all the calculations and such for all the various distributions, but as far as actually grasping the concepts, Statistics eludes me...
The United States invariably does the right thing, after having exhausted every other alternative. Winston Churchill
America is the only country that went from barbarism to decadence without civilization in between. Oscar Wilde
Wow, even the French showed a little more spine than that before they got their sh*t pushed in.[^] Colin Mullikin





Is in context with your pay. Your happiness is not correlated with how much you earn but how many standard deviations away from the norm you are in the positive direction. For example, if you earn more than 99% of your peers at 85k you are a lot happier than if you make 250k but you peers earn 300k.





It's a measure of how variable a collection of data is. Roughly speaking it's the distance from the mean in which a decent majority of the data points/probability distribution lie (for a pure normal distribution which is what it's most valid for it is ~60% if I remember right).





68%
People say nothing is impossible, but I do nothing every day.





If they did pure maths, they may not have done stats. However, I did it at a O level.





Statistics was my least favorite math(s) class in college. Most math seemed to make perfect sense, but statistics seemed so arbitrary. I mean, why not 96% instead of 95% confidence?





This was exactly my thought as well. I didn't see a huge practical use to a lot of the stuff we learned. Calculus, on the other hand, you can relate to physics, so it made perfect sense to me (most of the time... ).
Linear algebra was pretty straightforward most of the time as well, until it got to Singular Value Decomposition. That took a little while to be able to really grasp.
The United States invariably does the right thing, after having exhausted every other alternative. Winston Churchill
America is the only country that went from barbarism to decadence without civilization in between. Oscar Wilde
Wow, even the French showed a little more spine than that before they got their sh*t pushed in.[^] Colin Mullikin





Understood statistics (then) but had a bear of a time with calculus.





djj55 wrote: had a bear of a time with calculus.
Me too! I had to take it twice just to keep it from destroying my GPA. The second goround was much better. I still have an awesome study guide (paperback) that really made the difference for me. I actually enjoyed it once I got my head around it. (or accepted that it just worked, whether or not it actually made sense!) I would have loved to have the resources that students today enjoy...a global library at your fingertips!
"Go forth into the source"  Neal Morse





Because 95.45% of the values lie within 2 standard deviations of the mean.
That rounds down to 95, not up to 96.
Or did I misunderstand your question now?
People say nothing is impossible, but I do nothing every day.





Why not 3 standard deviations?





That would require a larger sample.
Statistics is all about finding out an approximate "truth" within an acceptable error margin to the lowest possible cost.
XKCD[^] has a fitting joke about it, as expected.
People say nothing is impossible, but I do nothing every day.





I was told by an MBA to remove Standard Deviation from a web page because it was too techy. When I defined the number he said, well, "Change Standard Deviation to Variance it sounds less technical" but he wanted me to keep the standard deviation as the number displayed *rolls eyes*, I changed the field to Variance and the number to Variance, he never noticed.





You could have used the word "Variation" and kept the standard deviation computation.
Software Zen: delete this;





I once had to explain to an English Major what a "Unreliable Narrator" was. Why this was important in understanding many fantasy, science fiction works both printed and dramatic, and even in modern political discourse.
My wife didn't speak to me for the rest of the day.





kmg365 wrote: My wife didn't speak to me for the rest of the day. Sounds familiar. My wife has an M.A. in English.
She absolutely hates it when I correct her spelling or grammar.
Software Zen: delete this;





Funnily I once had the opposite experience, an exGF English BA who was a brilliant writer in terms of vocabulary and imagination, but bad in grammar and punctuation, who positively welcomed my feedback on her output.
Her version of "Once more unto the breach..." paraphrased in the style of Bukowski got her an A, even though they were really asking for an analysis of the original text, because (as the lecturer said) it illustrated a deep understanding of both writers. Remains one of the bluest and entertaining bits of prose I've ever read.





My wife is great in the ideas department, but her mechanics were dreadful. For example, my favorite of her essays was entitled "Horror Fiction: The Most Useful Art Form". It had the thesis that horror fiction was the most valuable form of literature, because it taught the reader survival skills for unusual situations. She got an A, despite the fact that the professor hated genre fiction of all kinds, and horror fiction in particular.
I typed most of her undergraduate papers, and all of them for her master's. At least 0.5 of her GPA is attributable to my editing.
Software Zen: delete this;






Yes, although her favorite authors are Stephen King and H. P. Lovecraft.
Software Zen: delete this;





I missed the Stats bit on my Degree and avoided the catch up lectures as I was too bothered I didn't understand Fourier stuff well enough. That being said I did meet the principle at GCSE! Too much of Maths is badly taught so the chances are the Person knew the princple but not the way it was asked, it's Friday afternoon after all!
Glenn





I did Pure and Applied maths ALevels 23 years ago.
No standard deviations mentioned...
I did an extra Stats course in Uni to rectify that.





My software displays ZScore graphs for variable values based on the underlying selection  I am often asked to explain ZScores  my explanations rarely get beyond "ooh, look at the pretty graphs"





Just tell them the concept was originated by Guinness.
Yes, I know that's the tstatistic, but the zscore is related...
The United States invariably does the right thing, after having exhausted every other alternative. Winston Churchill
America is the only country that went from barbarism to decadence without civilization in between. Oscar Wilde
Wow, even the French showed a little more spine than that before they got their sh*t pushed in.[^] Colin Mullikin





Was it? That should get me off the hook, thanks





Imagine that. Interesting statistics and great grog.
Software Zen: delete this;





I got 98% for a mock stats exam in uni, and aced the real thing in less than a third of the available time.
I wouldn't know my sigma from my epsilon now, though. How soon useless crap is forgotten...
I wanna be a eunuchs developer! Pass me a bread knife!





Mark_Wallace wrote: How soon useless crap is forgotten... The part of my brain used for the 36+ credit hours of math I took in college (calculus, differential equations, matrix algebra, numerical methods) is now used to store old movie lines.
Software Zen: delete this;





Standard deviation is the difference between the lowest and highest beer count after which 68% of the male population will fall under the table.
Divided by two.





Isn't that 'staaahhd deevshun'?





Statistics wasn't required at my college, but I chose to take it  partly because I could rely on my father to help me as needed (he taught it at another college).
I still recall the time during my coop job when I was asked to rewite a report that was supposed to present the standard deviation  all it was doing to dividing the average (arithmetic mean) by the size of the population . I have no idea who wrote it originally, but I fixed it good*.
* I chose this wording due to the grammar discussion.



