Related Experiment Video
Updated: Aug 17, 2026

Assessing Differences in Sperm Competitive Ability in Drosophila
Published on: August 22, 2013
The mean and variance of the selection differential after top-down selection from a mixture of normal samples
1Faculty of Psychology, University of Ghent, Belgium. wilfried.decorte@ugent.be
Abstract:
A procedure is presented for determining the mean and variance of the selection differential for top-down selections in which the candidates come from populations that have a different average score on the selection measure. Although the procedure is based on the same stochastic model and requires identical data to the currently available method for estimating the mean selection differential, it has the advantage that the resulting expressions are valid for finite-sample selection decisions and that the variance of the selection differential can also be assessed. The difference between the two procedures is illustrated by means of an example application, and it is shown how the present results are particularly helpful in determining the expected utility of personnel selection decisions.
Related Concept Videos
Sampling Distribution
One-Way ANOVA: Equal Sample Sizes
Different sample means can result in different values for the variance estimate: variance between samples. This is because the variance between samples is calculated as the product of the sample size and the variance between the...
Student t Distribution
The Student t distribution was developed by William S. Goset (1876–1937) of the...
Estimating Population Mean with Unknown Standard Deviation
William S. Gosset (1876–1937) of the Guinness...
Choosing Between z and t Distribution
Variation: Normal Distribution, Range, and Standard Deviation
