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Do both terms mean the same thing or are they different?

amoeba
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ankit
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1 Answers1

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Mean deviation is the same as mean absolute deviation; it is mean deviation from the mean. $$ MAD=\frac{1}{N}\sum_{i=1}^{N}|x_i-\overline{x}| $$

Mean absolute difference is for two independent values $X$ and $Y$ $$ MD=E[|X-Y|] $$

Andrey Kolyadin
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  • I couldn't comprehend the second formula notations (namely "E" and square brackets use). Can you help? – ankit Nov 25 '16 at 12:22
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    it's expected value of variable, you can read a [Wikipedia page](https://en.wikipedia.org/wiki/Expected_value) for some information. – Andrey Kolyadin Nov 25 '16 at 12:27
  • @ankit see [Mean absolute difference](https://en.wikipedia.org/wiki/Mean_absolute_difference) on Wikipedia for an equivalent equation for mean absolute difference that may be more comprehensible. $$\frac{1}{n^2} \sum_{i=1}^{n} \sum_{j=1}^{n} |x_i -y_j|$$ – franzo Jun 12 '20 at 00:29