🚀 go-pugleaf

> Robin Bingham [SMTP:Rbingham@WESTERN.EDU]  wrote:
>
>   > Can anyone explain "error propagation"?  Apparently this method is
> used to
>   > obtain a variance for a ratio.
>
> Ratios of normally distributed quantities, such as many environmental
> variables, do not have a variance.  Consult a statistics textbook for
> more details, or read the following references regarding the practical
> applicability of ratios:
>
> Amjad, S., and J.S. Gray.  1983.  Use of the nematode-copepod ratio as
> an index of organic pollution.  Marine Pollution Bulletin 14(5):
> 178-181
>
> Atchley, W.R., C.T. Gaskins, and D. Anderson.  1976.  Statistical
> properties of ratios.  I.  Empirical results.  Syst. Zool. 25: 137-148
>
> Berges, J.A.  1997.  Ratios, regression statistics, and "spurious"
> correlations.  Limnology and Oceanography 42(5): 1006-1007
>
> Doctor, P.G., R.O. Gilbert, and J.E. Pinder III.  1980.  Appropriate
> use of ratios in environmental transuranic studies.  in Transuranic
> Elements in the Environment, W.C. Hanson, ed. pp. 187-208
>
> Jackson, D.A., H.H. Harvey, and K.M. Somers.  1990.  Ratios in aquatic
> sciences: statistical shortcomings with mean depth and the
> morphoedaphic index.  Canadian Journal of Fisheries and Aquatic
> Science 47: 1788-1795
>
> Packard, G.C., and T.J. Boardman.  1987.  The misuse of ratios to
> scale physiological data that vary allometrically with body size.  in
> New Directions in Ecological Physiology, M.E. Feder, A.F. Bennett,
> W.W. Burggren, and R.B. Huey, eds.  Cambridge University Press, Cambri
> pp 216-236
>
> Packard, G.C., and T.J. Boardman.  1988.  The misuse of ratios,
> indices, and percentages in ecophysiological research.  Physiological
> Zoology 61(1): 1-9
>
> Phillips, R.B.  1983.  Shape characters in numerical taxonomy and
> problems with ratios.  Taxon 32(4): 535-544
>
> Rempel, R.S., and P.J. Colby.  1991.  A statistically valid model of
> the morphoedaphic index.  Canadian Journal of Fisheries and Aquatic
> Science 48: 1937-1943
>
> Tracy, C.R., and J. Sugar.  1989.  Potential misuse of ANCOVA: Comment
> on Packard and Boardman.  Physiological Zoology 62(4): 993-997
>
> Varnell, L.M., K.J. Havens, and C. Hershner.  1995.  Daily variability
> in abundance and population characteristics of tidal salt-marsh fauna.
> Estuaries 18(2): 326-334
>
> Welsh, A.H., A.T. Peterson, and S.A. Altmann.  1988.  The fallacy of
> averages.  American Naturalist 132: 277-288
>