There is some ambiguity about the definition of the coefficient of
variation!
Both Chatfield (in Statistics for Technology) and Kirkwood and Sterne (in
Essential Medical Statistics, 2003) use the definition of the ratio of the
standard deviation to the mean, expressed as a percentage.
The first reference given below by Paul Johnson replaces 'standard
deviation' by 'standard error', which clearly has quite a different meaning.
Are both definitions in common use? Such duality of meaning is confusing!
Sarah
________________________________________________________________
Dr Sarah A White
Statistician, MLW Clinical Research Programme,
College of Medicine, P O Box 30096, Chichiri, Blantyre 3, MALAWI
Noori
Here are a couple of links that may be of help
and mention these results.
http://sherlock.uqar.uquebec.ca/ENQ-10055/doc/chapt9.pdf
http://www.hc-sc.gc.ca/pphb-dgspsp/publicat/dic-dac2/english/55appendix_a_e.
html
Paul Johnson
http://www.biostatsoftware.com
--- Noori Akhtar-Danesh <[log in to unmask]>
wrote:
> Dear folks,
>
> I have received a comment from a reviewer for a
> submitted manuscript that:
>
> "If CV (coefficient of variation) is > 33.3, the
> results should not be included in any reporting. If
> CV is between 16.6 and 33.3, you should add a
> caution to the results such as: interpret with
> caution as CV is between 16.6 and 33.3."
>
> Is there any concrete reference to support this
> statement in general?
>
> Many thanks for your help,
>
> Noori
>
> ============================
> Noori Akhtar-Danesh,
> Statistician, PhD
> Faculty of Health Sciences,
> Room 3N28B
> McMaster University,
> 1200 Main St. West,
> Hamilton, ON L8N 3Z5,
> CANADA
> =============================
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