We extend the optimal symmetric group sequential tests of Eales & Jennison (1992) to the broader class of asymmetric designs. Two forms of asymmetry are considered, involving unequal type I and type II error rates and different emphases on expected sample sizes at the null and alternative hypotheses. We discuss the properties of our optimal designs and use them to assess the efficiency of the f...

The purpose of this study was to examine the effect of 10 weeks' 40-m repeated sprint training program that does not involve strength training on sprinting speed and repeated sprint speed on young elite soccer players. Twenty young well-trained elite male soccer players of age (±SD) 16.4 (±0.9) years, body mass 67.2 (±9.1) kg, and stature 176.3 (±7.4) cm volunteered to participate in this study...

Twenty years of testing in the field has consistently revealed that food intake is inadequate when packaged military rations are fed as the sole source of food. Food intake is much lower and there is a loss of body weight. Conversely when these rations are fed to students or military personnel for periods ranging from 3 to 42 days in a cafeteria-like setting, food intake is comparable to levels...

Most randomised trials allocate individual participants to different treatments. However, cluster randomised trials in which groups of subjects are allocated to different treatments are becoming increasingly popular. Cluster randomisation is often advocated to minimise treatment “contamination” between intervention and control participants. For example, in a trial of dietary change, people in t...

Motivated by applications to goodness of fit U-statistics testing, the empirical likelihood approach is generalized to allow for the number of constraints to grow with the sample size and for the constraints to use estimated criteria functions. The latter is needed to handle naturally occurring nuisance parameters. The proposed empirical likelihood based goodness of fit tests are asymptotically...

The primary objective of this paper is to describe how site selection effects can influence the safety effectiveness of treatments. More specifically, the goal is to quantify the bias for the safety effectiveness of a treatment as a function of different entry criteria as well as other factors associated with crash data, and propose a new method to minimize this bias when a control group is not...