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Cyrille Joutard - One of the best experts on this subject based on the ideXlab platform.

Manuel Úbeda-flores - One of the best experts on this subject based on the ideXlab platform.

Brunnere. - One of the best experts on this subject based on the ideXlab platform.

Markus Neuhauser - One of the best experts on this subject based on the ideXlab platform.

  • advice on testing the null hypothesis that a Sample is drawn from a normal distribution
    Animal Behaviour, 2015
    Co-Authors: Graeme D Ruxton, David M Wilkinson, Markus Neuhauser
    Abstract:

    The normal distribution remains the most widely used Statistical model, so it is only natural that researchers will frequently be required to consider whether a Sample of data appears to have been drawn from a normal distribution. Commonly used Statistical packages offer a range of alternative formal Statistical tests of the null hypothesis of normality, with inference being drawn on the basis of a calculated P value. Here we review the Statistical literature on the performance of these tests and briefly survey current usage of them in recently published papers, with a view to offering advice on good practice. We find that authors in Animal Behaviour seem to be using such testing most commonly in situations in which it is inadvisable (or at best unnecessary) involving pretesting to select parametric or nonparametric analyses, and making little use of it in model-fitting situations in which it might be of value. Of the many alternative tests, we recommend the routine use of either the Shapiro–Wilk or Chen–Shapiro tests; these are almost always superior to commonly used alternatives such as the Kolmogorov–Smirnov test, often by a substantial margin. We describe how both our recommended tests can be implemented. In contrast to current practice as indicated by our survey, we recommend that the results of these tests are reported in more detail (providing both the calculated Sample Statistic and the associated P value). Finally, we emphasize that even the higher-performing tests of normality have low power (generally below 0.5 and often much lower) when Sample sizes are less than 50, as is often the case in our field.

Waleed A. Yousef - One of the best experts on this subject based on the ideXlab platform.

  • AUC: Nonparametric Estimators and Their Smoothness.
    arXiv: Machine Learning, 2019
    Co-Authors: Waleed A. Yousef
    Abstract:

    Nonparametric estimation of a Statistic, in general, and of the error rate of a classification rule, in particular, from just one available dataset through resampling is well mathematically founded in the literature using several versions of bootstrap and influence function. This article first provides a concise review of this literature to establish the theoretical framework that we use to construct, in a single coherent framework, nonparametric estimators of the AUC (a two-Sample Statistic) other than the error rate (a one-Sample Statistic). In addition, the smoothness of some of these estimators is well investigated and explained. Our experiments show that the behavior of the designed AUC estimators confirms the findings of the literature for the behavior of error rate estimators in many aspects including: the weak correlation between the bootstrap-based estimators and the true conditional AUC; and the comparable accuracy of the different versions of the bootstrap estimators in terms of the RMS with little superiority of the .632+ bootstrap estimator.