Gaining Market Share for Nonparametric Statistics. Michael J. Schell Moffitt Cancer Center University of South Florida. Web of Science. Source of count data for this talk Words/phrases found in title or abstract Mainly title only references before 1991
Michael J. Schell
Moffitt Cancer Center
University of South Florida
Sub-Field 1990-94 2005-07* GR
Non-linear 1469 2494 3.4
Wavelets 1025 6114 11.9
Linear 4360 8281 3.8
Logistic 4291 16,728 7.8
Mixed models 750 2817 7.5
Data mining 11 2979 542
Bioinformatics 14 4194 599
* Estimated 5-year rate obtained by doubling the count
GR = Growth Rate
Arbitrarily small departures from normality result in low power; even when distributions are normal, heteroscedasticity can seriously lower the power of standard ANOVA and regression methods.
… most quantitative articles tend to be too technical for applied researchers.
If the goal is to avoid low power, the worst method is the ANOVA F test.
…the Theil-Sen estimator deserves consideration as well.
The scandal of poor medical research, 1994
Why are errors so common? Put simply, much poor research arise because researchers feel compelled for career reasons to carry out research that they are ill equipped to perform, and nobody stops them.
Statistics and ethics in medical research. The misuse of statistics is unethical, 1980
In an environment where ideas are not marketed, first on the market wins
Kolmogorov-Smirnov test, 1937
Duncan’s test, 1950
Kaplan-Meier curves, 1958
Cox regression, 1972
Chernoff and Savage (1958) proved that the ARE of the normal scores test is at least 1
“The above results suggest that on the basis of power, at least for large samples, both the Wilcoxon and normal scores tests are preferable to the t-test for general use.”
Conclusion: t-test is fine, exponential distribution simulation was done wrong
Highest citation count on any subsequent simulation study (39 thru 2000) = 96
Basic Practice of Statistics, 4th Ed. 2006 David S. Moore (728 pages)
Non-parametric tests don’t make the book; they appear in the virtual appendix.
Statistics: A Biomedical Introduction, 1977
Hollander and Wolfe
T-test in Chapter 5; Wilcoxon in Chapter 13
Biostatistics, 2nd Ed. van Belle, Fisher, et al., 2004
T-test in Chapter 5; Wilcoxon in Chapter 8
Book N Mn SD Sk Kurt Range Md
1 41 15.0 9.3 1.9 4.6 5-50 12
2 31 15.0 8.0 1.1 0.9 5-36 12
3 17 21.1 16.7 2.3 5.4 7-72 18
4 17 18.9 13.2 1.2 0.5 5-48 15
5 44 15.9 26.1 5.6 34.5 2-43,176 9
It has been my experience as a statistician in cancer research, that we are:
Thus, nonparametric analysis has predominated in my applied articles
Applied statistical work is very important in decision-making
Educators have an ethical responsibility to properly train their “tool user” students in best practices
“Tool user” statisticians have an ethical responsibility to seek best practice information