variance /var·i·ance/ (var´e-ans) a measure of the variation shown by a set of observations: the average of the squared deviations from the mean; it is the square of the standard deviation.
variance
deviation [de″ve-a´shun]
var·i·ance (vâr  - ns, v r-)n. 1. The state or quality of being variant or variable; a variation. 2. The state or fact of differing or of being in conflict. 3. The square of the standard deviation. |
variance
[ver′ē·əns]
Etymology: L, variare
1 (in statistics) a numeric representation of the dispersion of data around the mean in a given sample. It is represented by the square of the standard deviation and is used principally in performing an analysis of variance.
2
Usage notes: nontechnical.
the general range of a group of findings. deviation [de″ve-a´shun]
1. a turning away from the regular standard or course.
2. in ophthalmology, strabismus.
3. in statistics, the difference between a sample value and the mean.
axis deviation an axis shift in the frontal plane, as seen on an electrocardiogram. There are three types: Left, from −30° to −90°; Right, from +90° to +180°; and Undetermined, which may be either extreme left or extreme right, from −90° to +180°.
conjugate deviation dysfunction of the ocular muscles causing the two eyes to diverge to the same side when at rest.
sexual deviation sexual behavior or fantasy outside that which is morally, biologically, or legally sanctioned, often specifically one of the paraphilias.
standard deviation (SD) the dispersion of a random variable; a measure of the amount by which each value deviates from the mean. It is equal to the square root of the variance. For data that have a normal distribution, about 68 per cent of the data points fall within (plus or minus) one standard deviation from the mean and about 95 per cent fall within (plus or minus) two standard deviations. Symbol σ.
ulnar deviation a hand deformity, seen in chronic rheumatoid arthritis and lupus erythematosus, in which swelling of the metacarpophalangeal joints causes the fingers to become displaced to the ulnar side. Called also ulnar drift. See illustration.
Ulnar deviation (ulnar drift) of the metacarpophalangeal joint, a characteristic sign of rheumatoid arthritis. From Pedretti and Early, 2001.
variance
one of the measures of the dispersion of data; the mean squared deviation of a set of values from the mean.
additive genetic variance
that portion of phenotypic variance which is due to the additive effect of genes (VA).
analysis of variance
a statistical method for comparing values, expressed in terms of means or variance, of one or more variables in several subgroups of a population. Called also anova.
non-additive genetic variance
that portion of phenotypic variance which is due to epistatic interactions (VI) and dominance deviations (VD).
non-genetic variance
that portion of phenotypic variance which is due to non-genetic effects such as environment (VE).
phenotypic variance
a measure of the extent to which individuals vary in their phenotype (VP). VP = VA + VD + VI + VE.
variance ratio distribution
see f distribution.
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