skewed distribution

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Fig. 28 Skewed distribution. (a) Positively skewed distribution. (b) Negatively skewed distribution.

skewed distribution

a distribution of data obtained from a sample or population which does not show the NORMAL DISTRIBUTION of a bell-shaped curve. In a normal distribution the MEAN, MEDIAN and MODE fall in the same place – the curve is symmetrical. In a positively skewed distribution (Fig. 28a) the mode and median are less than the mean, while in a negatively skewed distribution (Fig. 28b) the mean is less than the median and mode. Some population characteristics have a normal distribution, e.g. height, others may be skewed, e.g. social class among students in higher education.
References in periodicals archive ?
E]), for which, as Swan and Tyworth (2001, 19) point out, "The gamma distribution is theoretically appealing because it has non-negative values and can approximate both bell-shaped and skewed distributions.
In the updated methodology, measures with potentially skewed distributions (percentage measures only) are instead scored with truncated z-scores, instead of probit scores.
For left skewed distributions, we note the following inequalities:
Since our purpose is primarily to gauge performance with skewed distributions, we consider a very clean, artificial as well as real datasets that exactly exhibit a well-understood type of skew, a power law.
These authors examined KR robustness with sample sizes of 30 and moderately skewed distributions, finding that KR was mainly liberal for both the repeated measures and interaction effects.
Westfall and Yang (1993) and Wilcox (2003; 2005) reported that testing the hypothesis regarding trimmed mean provides more reliable results in the skewed distributions.
Students should be able to: (i) explain why we had to wait more than 30 minutes for the average household (that is, the mean is greater than the median for positively skewed distributions of income), (ii) discuss the impact on the height of parade participants if we had considered individual incomes instead of household incomes, and (iii) prepare a graph that relates minutes (into the hour-long parade) on the horizontal axis and the height of the income recipients on the vertical axis.
A spokesperson explained that realistic field applications were used as the basis for demonstrating statistical tests, hypothesis tests were explained in light of data with non-detects, outliers, and skewed distributions, and methods for estimation and prediction were illustrated along with
This was done for both the even and skewed distributions.
Their Monte Carlo studies discovered that this test produced too many Type 1 errors when samples are drawn from leptokurtic or chi-square skewed distributions.