BACKGROUND Although non-normal data are widespread in biomedical research, parametric tests unnecessarily predominate in statistical analyses. METHODS We surveyed five biomedical journals and - for all studies which contain at least the unpaired t-test or the non-parametric Wilcoxon-Mann-Whitney test - investigated the relationship between the choice of a statistical test and other variables ...

This paper discusses a class of tests of lack-of-fit of a parametric regression model when design is non-random and uniform on [0,1]. These tests are based on certain minimized distances between a nonparametric regression function estimator and the parametric model being fitted. We investigate asymptotic null distributions of the proposed tests, their consistency and asymptotic power against a ...

Two tests of heterozygosity for phenylketonuria, the phenylalanine/tyrosine ratio in the plasma after a fast and the response to an oral load of phenylalanine, have been compared in obligate heterozygotes for phenylketonuria and apparent normal homozygotes. The discriminatory ability of the tests is measured using both parametric and non-parametric methods, the correlation between them is deter...

Listening tests and Mean Opinion Scores (MOS) are the most commonly used techniques for the evaluation of speech synthesis quality and naturalness. These are invaluable in the assessment of subjective qualities of machine generated stimuli. However, there are a number of challenges in understanding the MOS scores that come out of listening tests. Primarily, we advocate for the use of non-parame...

Advances in technology provide new diagnostic tests for early detection of disease. Frequently, these tests have continuous outcomes. One popular method to summarize the accuracy of such a test is the Receiver Operating Characteristic (ROC) curve. Methods for estimating ROC curves have long been available. To examine covariate effects, Pepe (1997, 2000) and Alonzo and Pepe (2002) proposed distr...

This study compared the relative statistical sensitivity of non-parametric and parametric statistics of 3-dimensional current sources as estimated by the EEG inverse solution Low Resolution Electromagnetic Tomography (LORETA). One would expect approximately 5% false positives (classification of a normal as abnormal) at the P < .025 level of probability (two tailed test) and approximately 1% fal...