Sample size/power calculation for stratified case-cohort design

Sample Size and Power Calculation in Microarray Studies Using the sizepower package

The process of obtaining biological samples is often expensive, involved, and time consuming. Thus, the issue of the appropriate sample size is important in planning a study. If the sample size is too large, we waste resources. If the sample size is too small, we cannot draw inferences with the desired precision. Thus, we need to calculate the sample size of a study before proceeding in order t...

Exposure stratified case-cohort designs.

A variant of the case-cohort design is proposed for the situation in which a correlate of the exposure (or prognostic factor) of interest is available for all cohort members, and exposure information is to be collected for a case-cohort sample. The cohort is stratified according to the correlate, and the subcohort is selected by stratified random sampling. A number of possible methods for the a...

Sample Allocation for Stratified Telephone Sample Designs

Case Study: Online Learning for Design and Calculation of Machines

In recent years, the University of Salamanca together with other 45 European universities have changed our university qualifications, resulting in substantial changes in the system of education. In this case study, we detail the particular case of the subject of Design and Calculation of Machines of the Degree in Mechanical Engineering, which is given at the School of Industrial Engineering at ...

Sample Size Calculation for Comparing Means

Sample size calculation plays an important role in clinical research. In clinical research, a sufficient number of patients is necessary to ensure the validity and the success of an intended trial. From a statistical point of view, if a clinically meaningful difference between a study treatment and a control truly exists, such a difference can always be detected with an arbitrary power as long ...