# Talk:Absolute deviation

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This article is within the scope of WikiProject Mathematics, a collaborative effort to improve the coverage of Mathematics on Wikipedia. If you would like to participate, please visit the project page, where you can join the discussion and see a list of open tasks.
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Field: Probability and statistics

## Average Absolute Deviation vs. Mean Absolute Deviation

This article is VERY poorly worded. In particular the "average absolute deviation" section claims that the 'average absolute deviation' is the same as the 'mean absolute deviation' which makes sense. However the following section is titled "mean absolute deviation" and gives an alternative definition which implies that the 'average absolute deviation' and the 'mean absolute deviation' are in fact different. The alternative definition also utilizes a variable 'Fi' which is not defined anywhere in the article. — Preceding unsigned comment added by 59.156.80.115 (talk) 05:27, 14 December 2011 (UTC)

I came to say the same thing. The two sections should be merged into one, and whoever created the secondmost of the two (rather than editing whatever was there first) must be shot at dawn. Glenbarnett (talk) 05:04, 11 July 2012 (UTC)

also Need to clarify what M means in "MAD" it's used for both mean absolute and median absolute. Please change the mean to AAD or only let it reference the one it actually represents... --184.158.56.62 (talk) 21:12, 10 November 2012 (UTC)

I've gone ahead and tried to clean up the section on the Average Absolute Deviations. It is still somewhat messy, but I no longer think there are duplicitous definitions. The article still seems unfocused, and could be better served by framing the uses of absolute deviations with contexts rather than just using formulas. Douglas Whitaker (talk) 18:53, 20 February 2013 (UTC)

The terminology usage was still poorly woven. I hope my updates are an improvement. LarryLACa (talk) 02:40, 24 August 2014 (UTC)

## expected value?

As a summary statistic, this isn't an expected value because it's not in regard to a random variable, but the actual data. Should the "expected value" be removed, or should it be described aas the expected value of something else? Cretog8 (talk) 20:12, 2 July 2008 (UTC)

## Contrast Section Needed

A contrast with standard deviation would help make this more clear for those less adept at math. I would add this, except I am less adept at math. 64.122.190.43 (talk) 16:36, 9 July 2010 (UTC)

## A Greek Symbol for the Mean Absolute Deviation?

For standard deviation, the Greek letter, σ, is used in statistics. Is there a Greek letter conventionally used for the Mean Absolute Deviation? Roland 01:19, 29 May 2013 (UTC)