Many assessment and evaluation studies use statistical hypothesis tests, such as the independent samples t test or analysis of variance, to test the equality of two or more means for gender, age groups, cultures or language group comparisons. In addition, some, but far fewer, studies compare variability across these same groups or research conditions. Tests of the equality of variances can ther...

The aim of this investigation was to determine, compare and evaluate three different computerized tracing programs, where the lateral cephalograms were digitized on the screen. 39 randomly selected cephalometric radiographs were used in the present study. Three programs Planmeca Romexis® (Romexis 3.2.0., Helsinki, Finland), Orthalis (France) and AxCeph (A.C 2.3.0.74, Ljubljana, Slovenia) were e...

This article introduces (and hopes to encourage thereby) the econometrics practitioner to (use) a homoscedasticity test referred to in the field of statistics as the modified Levene test. Econometrics orthodoxy (from University to practice level) has focused mainly on three heteroscedasticity tests, namely the Goldfeld-Quandt (GQ), Breusch-Pagan-Godfrey (BPG), and the White (W) test. The differ...

7 Davidson and Bogert, forthcoming publication. 8 Davidson and Bogert, forthcoming publication. 9 Behrend, Ann. Chem., 245, 213 (1888); Behrend and Ernert, Ibid., 258, 347 (1890). 10 Angeli, Atti. accad. Lincei, [5] 3, II, 72 (1894). 11 Johnson, Baudisch, and Hoffmann, loc. cit. 12 Levene, Bass, and Simms, J. Biol. Chem., 70, 229 (1926). 13 Behrend and Roosen, Ann. Chem., 251, 235 (1889). 14 Be...

We give an overview of the basic principles of approximate Bayesian computation (ABC), a class of stochastic methods that enable flexible and likelihood-free model comparison and parameter estimation. Our new open-source software called ABrox is used to illustrate ABC for model comparison on two prominent statistical tests, the two-sample t-test and the Levene-Test. We further highlight the fle...

To test for equality of variances given two independent random samples from univariate normal populations, popular choices would be the two-sample F test and Levene’s test. The latter is a nonparametric test while the former is parametric: it is the likelihood ratio test, and also a Wald test. Another Wald test of interest is based on the difference in the sample variances. We give a nonparamet...

In the first communication of this series [1913, 2] I expressed the view that the brain contains in a preformed condition mainly two representatives of the group of glucosides, namely the galactosides phrenosin and kerasin, which were originally discovered by Thudichum. A new method for their preparation was subsequently described together with a physical test (the selenite plate test) which fu...