Standardized difference scores are intuitive indexes which measure the effect size between two groups. Compared to a t-test or Wilcoxon rank-sum test, they are independent of sample size. Thus, their use can be recommended for comparing baseline covariates in clinical trials as well as propensity-score matched studies. In this paper, we show how to calculate sample standardized differences for ...

This procedure allows you to study the power and sample size of tests of equivalence of means of two correlated variables. Schuirmann’s (1987) two one-sided tests (TOST) approach is used to test equivalence. The paired t-test is commonly used in this situation. Other tests have been developed for the case when the data are not normally distributed. These additional tests include the Wilcoxon si...

To the Editor:-We read with interest the article by Zhou and Dexter on the use of prediction bounds to assist scheduling of add-on cases.‘ We acknowledge that the authors have addressed an important topic in operating-room efficiency; however, we have certain concerns as to the practical utility of the current version of this approach. Table 1 in their article supplies data on the quality of 50...

This paper's aim was to develop a conceptual overview of SMS marketing and delineate factors of new communications technologies on business practice. This study, which was a descriptive survey, was built on primary and secondary data source including a literature review of SMS marketing and a Questionnaire were used as the primary means of collecting secondary data. The sample size of 300 patie...

Positive Darwinian selection at the molecular level is often studied by comparing the number of synonymous nucleotide substitutions per synonymous site (d,) and the number of nonsynonymous substitutions per nonsynonymous site (dN) between homologous gene sequences, and a t-test with an infinite number of degrees of freedom is usually used for determining the statistical significance of the diff...

This study investigates the functional equivalence of two measures of irregular word pronunciation--National Adult Reading Test (NART) and Schonell--which are popular instruments used to assess verbal neurocognitive functioning and to estimate premorbid IQ. We report norms for the NART in a pooled sample from 3 Australian population-based studies of adults aged 65-103 years. Norms were stratifi...

Let's start with the most familiar context for pooling data (at least to students in introductory courses in statistics), viz., the pooling of sample variances in a t test of the significance of the difference between two independent sample means. The null hypothesis to be tested is that the means of two populations are equal (the populations from which the respective samples have been randomly...