A Proposed Test of the Difference Between the Means of Monozygotic And Dizygotic Twins
- 1 January 1977
- journal article
- research article
- Published by Cambridge University Press (CUP) in Acta geneticae medicae et gemellologiae
- Vol. 26 (1), 49-53
- https://doi.org/10.1017/s0001566000010187
Abstract
The rationale for using an approximate t′ test of the difference between the means of MZ and DZ twins is presented. This test avoids pooling the among-MZ and among-DZ twin-pair mean squares and has approximate degrees of freedom based upon the relative number of MZ and DZ twin pairs as well as the relative sizes of the among-MZ and among-DZ twin-pair mean squares. Sampling experiments simulating twin studies were used to show that the rate of Type I error for this t′ test was appropriate while other tests could give either too many or too few Type I errors depending upon the relative sizes of the mean squares and the relative numbers of MZ and DZ twin pairs.This publication has 3 references indexed in Scilit:
- Some Theorems on Quadratic Forms Applied in the Study of Analysis of Variance Problems, I. Effect of Inequality of Variance in the One-Way ClassificationThe Annals of Mathematical Statistics, 1954