Basic Definitions Used in Community Analyses
367
Coefficient of variation (C or C. V). A measure of the relative variability of samples.
Ideally one would like to reduce C. V. to a minimum.
The term is applied to the standard deviation when it is expressed as a percentage of
the sample mean; hence
where s = standard deviation of sample and x = sample mean.
CONTAGIOUS
It
X
DEGREES OF FREEDOM (v)
Figure A.2.2. The 5% significance levels of X 2 • When the X2 value lies between significance levels,
agreement with Poisson series is accepted at 95% probability level (P > 0.05). X2 below the lower
level indicates regular distribution; X2 above the upper level indicates contagious distribution.
[Reproduced from Elliott (1977) by permission of the Freshwater Biological Association.]
367
Coefficient of variation (C or C. V). A measure of the relative variability of samples.
Ideally one would like to reduce C. V. to a minimum.
The term is applied to the standard deviation when it is expressed as a percentage of
the sample mean; hence
where s = standard deviation of sample and x = sample mean.
CONTAGIOUS
It
X
DEGREES OF FREEDOM (v)
Figure A.2.2. The 5% significance levels of X 2 • When the X2 value lies between significance levels,
agreement with Poisson series is accepted at 95% probability level (P > 0.05). X2 below the lower
level indicates regular distribution; X2 above the upper level indicates contagious distribution.
[Reproduced from Elliott (1977) by permission of the Freshwater Biological Association.]