Talk:Standard deviation

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Field: Probability and statistics
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"Difference of data point from the mean"?

The article write :

First compute the difference of each data point from the mean[clarification needed](how is this named?), and square the result of each:
$\begin{array}{lll} (2-5)^2 = (-3)^2 = 9 && (5-5)^2 = 0^2 = 0 \\ (4-5)^2 = (-1)^2 = 1 && (5-5)^2 = 0^2 = 0 \\ (4-5)^2 = (-1)^2 = 1 && (7-5)^2 = 2^2 = 4 \\ (4-5)^2 = (-1)^2 = 1 && (9-5)^2 = 4^2 = 16. \\ \end{array}$

What is the real, conventional term for this concept :

• deviation from average/mean ?
• deviation score/score deviation from average/mean ?
• deviation error from average/mean ?
• variance from average/mean ?
• ... (something else)

Naming each step properly is important for understanding. I'am beginner in statistic and unable to clarify this myself. May someone more knowledgeable dig a bit to clarify and link to the proper article. Yug (talk) 11:00, 18 November 2013 (UTC)

When you go to the shops do you give a name to every corner never mind every step? Dmcq (talk) 13:50, 18 November 2013 (UTC)
Probably worth looking at Errors and residuals in statistics. I'm not sure that, in practice, the difference from the mean is often referred to as a residual. The term 'residual' is more often used when you're fitting a statistical model such as a regression model—but you can think of estimating the mean as a 'zeroth order' statistical model, as done in the example in that article. Qwfp (talk) 16:08, 18 November 2013 (UTC)
In Bevington's statistics text I remember reading that these are called dispersions from the mean.Dave mathews86 (talk) 07:22, 4 February 2014 (UTC)

Rapid calculation methods - R/d2

In industrial engineering and quality control we use sometimes R(range)/d2(n) to easily estimate an unbiased deviation from sample. The theory says it is very precise for n<10. I'm not a statistician so please correct me. -- 04:36, 11 February 2014 (UTC) — Preceding unsigned comment added by 187.78.178.203 (talk)