hamzah Posted March 22, 2004 Share Posted March 22, 2004 Lets say I have three values - 917, 914 and 913. Take an average I get 915 (approx). Now see how far each value is from the average... 917 - 915 = 2 915 - 914 = 1 915 - 913 = 2 (2+1+2)/3 = 2 (approx) so the value is (915 +/- 2) what is this method called? Link to comment Share on other sites More sharing options...
Neurocomp2003 Posted March 22, 2004 Share Posted March 22, 2004 ....method? this isn't a method its error measurement. Link to comment Share on other sites More sharing options...
Kedas Posted March 22, 2004 Share Posted March 22, 2004 LOL It does ring a bell of some statistical method with 'some result' but I can't remember. Link to comment Share on other sites More sharing options...
hamzah Posted March 22, 2004 Author Share Posted March 22, 2004 Neurocomp2003 said in post # :....method? this isn't a method its error measurement. yeah thats what I'm doing, error measurements...but the way I calculated it...does that technique have a name or anything? Link to comment Share on other sites More sharing options...
blike Posted March 22, 2004 Share Posted March 22, 2004 Thats almost like variance, which takes the sum of all the squares of the differences between the means and values and then divides by the number of samples. In your case, the variance would be: [math]http://blike.com/mimetex/mimetex.cgi?4$var=\frac{(1-2)^2+(2-2)^2+(3-2)^2}{3}[/math] grr..my cgibin sucks Link to comment Share on other sites More sharing options...
fafalone Posted March 22, 2004 Share Posted March 22, 2004 ..standard deviation? Link to comment Share on other sites More sharing options...
Glider Posted March 23, 2004 Share Posted March 23, 2004 Hamza is talking about the mean deviation. The measure of how much any given observation varies from the mean is a deviation. These will have either positive or negative values. The mean of them will always be zero (as the mean is the arithmetical centre of the data). So, to calculate the mean deviation, we ignore the sign (+ or -) which gives us for each deviation the absolute deviation, shown as |d|. So, the two ways of calculating the mean deviation is either: Sum of |x - mean| ---------------------- N or Sum of |d| ------------- N The Standard deviation is: (Sum of (X - mean)^2) The square root of: ----------------------------- N (or N-1 for the sample SD). Dang! I wish I knew how to use the formula doohickey. Link to comment Share on other sites More sharing options...
hamzah Posted March 23, 2004 Author Share Posted March 23, 2004 thanks Glider and the rest of you for your help Link to comment Share on other sites More sharing options...
wolfson Posted March 23, 2004 Share Posted March 23, 2004 You're working out the mean absolute deviation from the mean, but you really ought to use a more accurate value for the mean of the numbers. Link to comment Share on other sites More sharing options...
hamzah Posted March 23, 2004 Author Share Posted March 23, 2004 Well I've completed an experiment to determine the specific heat capacity of Aluminium...and the book quotes "910J/kg.k"...so I thought I'd stick to the same format as them. Link to comment Share on other sites More sharing options...
Fluent in Lies Posted March 29, 2004 Share Posted March 29, 2004 Diactine Standard Regulative Regression Link to comment Share on other sites More sharing options...
wolfson Posted March 29, 2004 Share Posted March 29, 2004 Fluent i do not think standard error and effective reduction is applicable at this level. Link to comment Share on other sites More sharing options...
Fluent in Lies Posted March 29, 2004 Share Posted March 29, 2004 Oh how terribly silly of me, what was i thinking *girlish giggle* Link to comment Share on other sites More sharing options...
wolfson Posted March 29, 2004 Share Posted March 29, 2004 Its ok Link to comment Share on other sites More sharing options...
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