Specific statistical tests are used when the null hypothesis (H0) is to be tested using nonparametric nominal or ordinal data. With nominal data, experimental results are expressed by proportions or frequencies. Chi-square or related tests (the Fisher's exact test or the rows by columns test) are appropriate for testing H0 with nominal data. Ordinal data permit arrangement of statistical result...

Parametric methods are commonly used despite evidence that model assumptions are often violated. Various statistical procedures have been suggested for analyzing data from multiple-group repeated measures (i.e., split-plot) designs when parametric model assumptions are violated (e.g., Akritas and Arnold (J. Amer. Statist. Assoc. 89 (1994) 336); Brunner and Langer (Biometrical J. 42 (2000) 663))...

The Authors Miriam Friedman Ben David is Professor of Medical Education, formerly Co-Director of the Clinical Skills Certification Programme at the Educational Commission for Foreign Medical Graduates (ECFMG) and Associate Dean at the Medical College of Pennsylvania, Philadelphia. Professor Friedman Ben David is currently at the Centre for Medical Education, Dundee, Scotland. Her main areas of ...

In the context of flexible exchange rates, Milton Friedman proposed that speculation must exert a stabilising influence upon prices to remain profitable. This generated a wealth of predominantly theoretical research into the behaviour of speculators, for which the results seem to depend critically upon the assumptions. Such theoretical models need to be tested against empirical evidence to dete...

This article first appeared in Economic Inquiry Vol. 40, no. 3. Reprinted by permission of the publisher, Western Economic Association International. runk: Can you help me find my keys? Passerby: Sure, where exactly did you drop them? Drunk: Way over there by the trash can. Passerby: Then why are you searching over here? Drunk: The light’s much better under the lamppost. —Milton Friedman (Econo...

Recently the Bundesbank claimed that monetary targeting has become considerably more di cult by the increased volatility of short term money growth The present paper investigates the impact of German money growth volatility on income velocity and money demand in view of Friedman s money growth volatility hypothesis Granger causality tests provide some evidence for a velocity volatility linkage ...