South Africa has a population of 51.8 million people of which 7.5% over the age of five has a disability according to the latest census data (Statistics South Africa 2014). This statistic on the national prevalence of disability should be interpreted with caution since psychosocial and neurological disabilities are not accounted for (Statistics South Africa 2014). The most recent data on disabi...

Although the κ statistic has been used widely as an indicator of rater agreement, there have been some concerns about the existence of different definitions and some peculiar results involving skewed data. This note evaluates different definitions of κ and also demonstrates that the problem with directly comparing κ values, especially for skewed data, can be avoided by comparing their significa...

BACKGROUND Spatial scan statistics are widely used for spatial cluster detection, and several parametric models exist. For continuous data, a normal-based scan statistic can be used. However, the performance of the model has not been fully evaluated for non-normal data. METHODS We propose a nonparametric spatial scan statistic based on the Wilcoxon rank-sum test statistic and compared the per...

Suppose that U is a U-statistic of degree two based on N random observations drawn without replacement from a nite population. For the distribution of a standardized version of U we construct an Edgeworth expansion with remainder O(N ?1) provided that the linear part of the statistic satisses a Cram er type condition.

Conditions for approximate frequentist validity of posterior credible sets based on the score statistic have been derived in the multiparameter case. These conditions can be helpful in supplementing similar conditions obtainable through the likelihood ratio statistic and the highest posterior density region. In the process, explicit expressions are given for the posterior quantiles of the score...

Huitema and McKean (Psychological Bulletin, 110, 291-304, 1991) recently showed, in a Monte-Carlo study, that five conventional estimators of first-order autocorrelation perform poorly for small (< 50) sample sizes. They suggested a modified estimator and a test for autocorrelation. We examine an estimator not considered by Huitema and McKean: the C-statistic (Young, Annals of Mathematical Stat...

In a recent article Jennrich and Satorra (Psychometrika 78: 545-552, 2013) showed that a proof by Browne (British Journal of Mathematical and Statistical Psychology 37: 62-83, 1984) of the asymptotic distribution of a goodness of fit test statistic is incomplete because it fails to prove that the orthogonal component function employed is continuous. Jennrich and Satorra (Psychometrika 78: 545-5...

This paper reports an experiment designed to detect the influence of strategic uncertainty on behavior in order statistic coordination games, which arise when a player’s best response is an order statistic of the cohort’s action combination. Unlike previous experiments using order statistic coordination games, the new experiment holds the payoff function constant and only changes cohort size an...

In this study, seismic activity trend of lower reaches of Yangtze River – Yellow Sea (Y-Y) seismic belt during 2011-2020 is predicted based on statistic analysis of historical earthquake data and seismic activity analysis of recent mid-strong earthquakes occurred in this area. Three potential seismic risk zones are indicated where the destructive earthquakes might occur which will cause damages...

BACKGROUND The majority of cancer survivors are aged ≥ 65 years, yet, historically, cancer research has focused infrequently on older patients. The objective of this study was to examine predictors of physical function within a framework that integrates the gerontologic and oncologic needs of older cancer survivors. METHODS Path analysis tested 759 women who were breast cancer survivors aged ...