Objectives: The goal of this research was to compare lateral cephalometric radiography and cavum radiography in nasopharyngeal airway space evaluation. Methods: The sample of this study consisted of 36 Brazilian mouth breathing children, no racial distinction, with ages ranging from 5 to 12. These children were selected in Recife/PE, Brazil (2005) and divided into 6 groups. In each group, the r...

Scientists often use the Chi-square (χ) test to determine the “goodness of fit” between theoretical and experimental data. In this test, we compare observed values with theoretical or expected values. Observed values are those that the researcher obtains empirically through direct observation. The theoretical or expected values are developed on the basis of an established theory or a working hy...

The original chi-square test, often known as Pearson’s chi-square, dates from papers by Karl Pearson in the earlier 1900s. The test serves both as a ”goodnessof-fit” test, where the data are categorized along one dimension, and as a test for the more common ”contingency table”, in which categorization is across two or more dimensions. Voinov and Nikulin, this volume, discuss the controversy ove...

The Chi-square statistic is a non-parametric (distribution free) tool designed to analyze group differences when the dependent variable is measured at a nominal level. Like all non-parametric statistics, the Chi-square is robust with respect to the distribution of the data. Specifically, it does not require equality of variances among the study groups or homoscedasticity in the data. It permits...

The objective of the study is to analyze if there is a relationship between health and environmental sustainability concerns in food choices. We used data of 300 Italian consumers collected through a vis-à-vis survey. We performed cross-tabulations and chi-square tests for a selected set of variables measuring both types of concerns, segmenting the sample by age, gender and education. Our resul...