## area sampling

Overview page. Subjects: Public Health and Epidemiology — Probability and Statistics.

Sampling with primary sampling units (see cluster sampling) that are non-overlapping regions of the earth's surface. Examples of such regions are parishes, counties, fields, political...

## cartogram

Overview page. Subjects: Public Health and Epidemiology — Probability and Statistics.

A diagrammatic map that presents statistical information visually. This may be done in various ways, the best known of which is a choropleth map, in which regions are color-coded or...

## cross-over trial

Overview page. Subjects: Probability and Statistics — Medicine and Health.

A trial in which each of the groups in the study receive each of the treatments, but in a randomized order: each group will begin in one arm of the trial, but will, by design, cross over to...

## deviance

Overview page. Subjects: Public Health and Epidemiology — Probability and Statistics.

A measure for judging the extent to which a model explains the variation in a set of data when the parameter estimation is carried out using the method of maximum likelihood. The deviance, *D*null...

## John Graunt

Overview page. Subjects: Probability and Statistics — Public Health and Epidemiology.

(1620–74; b. London, England; d. London, England)

Prosperous London haberdasher and Freeman of the Drapers' Company. Graunt became interested in the information implicit in the...

## midrange

Overview page. Subjects: Sports and Exercise Medicine — Probability and Statistics.

For a set of numerical data the midrange is the arithmetic mean of the greatest and least values in the set. It is sometimes used as a measure of location, but it is unreliable, since, by...

## number needed to treat

Overview page. Subjects: Probability and Statistics — Public Health and Epidemiology.

(NNT)

The number of people who must be exposed to a specific intervention to see one occurrence of a specific outcome.

## ordinal variable

Overview page. Subjects: Probability and Statistics — Sports and Exercise Medicine.

A categorical variable in which the categories have an obvious order (e.g. strongly disagree, disagree, neutral, agree, strongly agree). Specialist models are required for ordinal variables...

## reliability

Overview page. Subjects: Medicine and Health — Probability and Statistics.

The sampling variance of a statistic. For example, the reliability of where σ^{2}=Var (*X*) so, as the sample size increases, *X̄*
_{
n
} becomes a better...

## skew

Overview page. Subjects: Medicine and Health — Probability and Statistics.

(in statistics)

A measure of the symmetry of a frequency distribution. If frequent scores are clustered at the lower end of the distribution and the tail points towards the higher...