Meta-analysis is a statistical method that is increasingly utilized to combine and compare the results of previous primary studies. However, because of the lack of comprehensive guidelines for how to use meta-analysis, many meta-analysis studies have failed to consider important aspects, such as statistical programs, power analysis, publication…

Purpose: The purpose of this study was to investigate the characteristics of missing physical activity (PA) data of children and youth. Method: PA data from the Chinese City Children and Youth Physical Activity Study ("N" = 2,758; 1,438 boys and 1,320 girls; aged 9-17 years old) were used for the study. After the data were sorted by the…

Good quality data is paramount for applied economic research. If the data are distorted, corresponding conclusions may be incorrect. We demonstrate how Benford's law, the distribution that first digits of numbers in certain data sets should follow, can be used to test for data abnormalities. We conduct an analysis of nine commonly used data sets…

Secondary data analysis as a methodological approach is not without its critics. Indeed, three main objections to the use of secondary data analysis in social research stand out: first that because of the socially constructed nature of social data, the act of reducing it to a simple numeric form cannot fully encapsulate its complexity. Secondly,…

This article presents the author's address at the 2007 "Journal of Applied Quantitative Methods" ("JAQM") prize awarding festivity. The festivity was included in the opening of the 4th International Conference on Applied Statistics, November 22, 2008, Bucharest, Romania. In the address, the author reflects on three theses that…

Demonstrates that some commonly used indices can be misleading in their quantification of reliability. The effects are most pronounced on gain or difference scores. Proposals are made to avoid sources of invalidity by using a procedure to assess reliability in terms of upper and lower limits for the true scores of each examinee. (Author/JDH)

A limitation of the principal components method is its scale dependence. This note shows that the method is scale invariant if the normalization is modified in an obvious way. Then the effect of a change in units is as transparent as in linear regression, and principal components can be used without apology. Most researchers who use multivariate…

School leaders are faced with the daunting task of anticipating the future and making conscious adaptations to their practices, in order to keep up and to be responsive to the environment. To succeed in a rapidly changing and increasingly complex world, it is vital that schools grow, develop, adapt and take charge of change so that they can…

Global economic transformations have never been as dramatic as in the twentieth century. Most countries have experienced radical changes in the standards of income per capita, technology, fertility, mortality, income inequality and the extent of democracy in the course of the past century. It is the goal of many disciplines--economics, history,…