This paper discusses power and sample-size computation for likelihood ratio and Wald testing of the significance of covariate effects in latent class models. For both tests, asymptotic distributions can be used; that is, the test statistic can be assumed to follow a central Chi-square under the null hypothesis and a non-central Chi-square under the alternative hypothesis. Power or sample-size c...

BACKGROUND Malocclusion should be identified at its earliest before it produces any detrimental effects. The objective of this study is to evaluate the orthodontic status and treatment need of school children in Telangana region, Andhra Pradesh, using Dental Aesthetic Index. MATERIALS & METHODS One thousand children in the age group of 12 - 14 years who fulfilled the inclusion and exclusion c...

Various chi-square statistics are used for testing structural equation models. A commonly used chi-square is the Satorra-Bentler (SB) statistic. This is a normal-theory chi-square corrected for non-normality in the observed variables. The relationship between the SB statistic and kurtosis is developed and it is shown that the SB statistic tends to decrease with increasing kurtosis if the model ...

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...