topic Re: Calculate mean deviation of the mean in Discussions

Calculate mean deviation of the mean

Lorien — Sun, 13 Aug 2017 11:28:07 GMT

I'm a beginner in statistics and JMP.

I have a column with text lengths. I managed to calculate the mean text length. But now I need to calculate the mean deviation of the mean text length.

Is this the same as the standard deviation of the column with text lengths or is this another calculation? And how do I do it in JMP?

Thank you for your help.

Re: Calculate mean deviation of the mean

txnelson — Sun, 13 Aug 2017 12:03:55 GMT

My suggestion would be that you take that new column, which contains the text length for the entry for the column, and then run

Analyze==>Distribution

on the new column. It will provide you with the Mean, STD, STD Error of the Mean, etc.

Re: Calculate mean deviation of the mean

Lorien — Sun, 13 Aug 2017 20:46:00 GMT

And is the standard deviation of that column with text lengths then the same as the mean deviation of the mean text length?

I don't get the concept 'mean deviation of the mean' entirely.

Re: Calculate mean deviation of the mean

txnelson — Mon, 14 Aug 2017 01:52:17 GMT

The standard deviation is different than the mean deviation. The mean deviation is simply taking the the average of the absolute value of the mean subtracted from each value.

use

If you created a new column and used the following formula

abs(:text length - col mean(:text length))

and then run the Distribution on that new column, the displayed mean would be the Mean Deviation

Re: Calculate mean deviation of the mean

Lorien — Mon, 14 Aug 2017 18:50:10 GMT

Ok, I understand.

Last question, is the standard deviation of the mean text length yet another calculation or is that just the S.D. of the column with text lengths?

Thanks!