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This is an old revision of this page, as edited by CarlWesolowski (talk | contribs) at 20:14, 24 March 2020 (Dr. Giles's comment on this article). The present address (URL) is a permanent link to this revision, which may differ significantly from the current revision.

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"Regression ratio"/"learning ratio"? When measuring the performance of a predictive model (e.g. regression) you can divide the RMSD by the standard deviation of the target data. When greater than or equal to one you have no learning better than the simple guessing of the mean of the data. When less than one, the prediction is more informative than just the mean. My question is: what is this measure commonly called? Uncoolbob 21:05, 15 January 2007 (UTC)[reply]

Update: colleagues are suggesting "Normalized RMSE" (or "Normalised RMSD"). Is this in wide enough use to add to the article? Uncoolbob 16:15, 16 January 2007 (UTC)[reply]

It is certainly wide enough in my field (Bioinformatics) to be useful and pertinent. The is a lot more to the story of "RMSD" than we have in this article. It could also use a lot more math theory. I also have a programme I wrote in C for calculating RMSD (it is impressively fast) and will upload the code to this site soon.--Thorwald 01:52, 17 January 2007 (UTC)[reply]

How does one interpret the RMSE value? If some results from my research yield a RMSE of, say 0.01 when comparing to an idealised estimator, what does that tell me? How can one tell if the RMSE is high or low? I think this information would be useful in this article. --Utsutsu (talk) 01:29, 3 February 2010 (UTC)[reply]

What are the xmin and xmax to be used for the normalized RMSE computation? Should it be the range of the first variable, the second or both? -- Danielgenin (talk) 17:22, 28 December 2010 (UTC)[reply]

This is not a good article. The words are unnecessarily wordy - oblong for example. There is also unnecessary complexity such as the use of vectors to help explain the concept. The article should be simplified. — Preceding unsigned comment added by 142.52.81.11 (talk) 05:10, 6 September 2012 (UTC)[reply]

Dr. Giles's comment on this article

Dr. Giles has reviewed this Wikipedia page, and provided us with the following comments to improve its quality:


"For an unbiased estimator, the RMSD is the square root of the variance, known as the standard error." Comment: 'standard error' should be replaced by 'standard deviation'. The term 'standard error' is universally used to refer to an estimated standard deviation, not the standard deviation itself.


We hope Wikipedians on this talk page can take advantage of these comments and improve the quality of the article accordingly.

Dr. Giles has published scholarly research which seems to be relevant to this Wikipedia article:


  • Reference : David E. Giles, 2012. "A Note on Improved Estimation for the Topp-Leone Distribution," Econometrics Working Papers 1203, Department of Economics, University of Victoria.

ExpertIdeasBot (talk) 16:59, 19 May 2016 (UTC)[reply]

 Done +mt 21:05, 19 May 2016 (UTC)[reply]

Strange as it may seem, variance is unbiased, but standard deviation is small number biased---see https://stats.stackexchange.com/questions/249688/why-are-we-using-a-biased-and-misleading-standard-deviation-formula-for-sigma for a discussion of this. I would suggest changing the sentence to read "RMSD-squared is the variance, which is unbiased. RMSD itself, A.K.A. standard deviation, has small number bias https://stats.stackexchange.com/a/27984/99274CarlWesolowski (talk) 20:14, 24 March 2020 (UTC)[reply]