Biomedical subjects
Publications and source records attributed to K J Berry.
Each of N judges independently assigns K distinct ranks to K objects. A method is described which provides the exact point probability, exact one-sided P value, and exact two-sided P value of the observed sum of N ranks for a specified object.
An algorithm and FORTRAN program are presented for the Terpstra-Jonckheere test statistic and associated probability value based on a randomization routine.
Exact and Monte Carlo resampling FORTRAN programs are described for the Wilcoxon-Mann-Whitney rank sum test and the Kruskal-Wallis one-way analysis of variance for ranks test. The program algorithms compensate for tied values and do not depend on asymptotic approximations for probability values, unlike most algorithms contained in PC-based statistical software packages.
An asymmetrical test of homogeneity of proportions possesses distinct advantages over a symmetrical test. The symmetric chi square test of homogeneity is widely employed in psychological research. An asymmetrical alternative to the chi square test of homogeneity is proposed and described.
The Fisher transformation of the sample correlation coefficient r (1915, 1921) and two related techniques by Gayen (1951) and Jeyaratnam (1992) are examined for robustness to nonnormality. Monte Carlo analyses compare combinations of sample sizes and population parameters for seven bivariate distributions. The Fisher, Gayen, and Jeyaratnam approaches are shown to provide useful results for a bivariate normal distribution with any population correlation coefficient rho and for nonnormal bivariate distributions when rho = 0. In contrast, the techniques are virtually useless for nonnormal bivariate distributions when rho not equal to 0.0. Surprisingly, small samples are found to provide better estimates than large samples for skewed and symmetric heavy-tailed bivariate distributions.
A FORTRAN program is provided for testing linear trend and homogeneity in proportions. Trend is evaluated by the Cochran-Armitage method and homogeneity is tested by an overall X2 test as well by multiple pairwise comparisons by the Fisher-Irwin exact method. The program should be easy to implement on any size of computer with a FORTRAN compiler.
Soil samples were randomly collected from 422 vegetable gardens in a study area centered in downtown Baltimore, Maryland, and having a radius of 48.28 km (30 miles). The levels of lead, four other metals (cadmium, copper, nickel, and zinc), and pH were measured for each location. The application of multi-response permutation procedures, which are compatible with mapping techniques, reveals that lead (as well as cadmium, copper, nickel, and zinc) is concentrated and ubiquitous within the soils of the inner-city area of Metropolitan Baltimore. The probability values that the concentration of metals occurred by chance alone vary from about 10(-15) to 10(-23) depending on the metal considered. Our findings pose environmental and public health issues, especially to children living within the inner-city.
1 The affinity of 17 compounds for muscarine-sensitive acetylcholine receptors in atrial pacemaker cells and ileum of the guinea-pig has been measured at 29 degrees C in Ringer-Locke solution. Measurements were also made at 37 degrees C with 7 of them. 2 Some of the compounds had much higher affinity for the receptors in the ileum than for those in the atria. For the most selective compound, 4-diphenylacetoxy-N-methylpiperidine methiodide, the difference was approximately 20-fold. The receptors in the atria are therefore different the structure from those in the ileum. 3 The effect of temperature on affinity are not the same for all the compounds, tested indicating different enthalpies and entropies of adsorption and accounting for some of the difficulty experienced in predicting the affinity of new compounds.