Finding Alternatives to the Dogma of Power Based Sample Size Calculation: Is a Fixed Sample Size Prospective Meta-Experiment a Potential Alternative?

Principles of sample size calculation

In most areas in life, it is difficult to work with populations and hence researchers work with samples. The calculation of the sample size needed depends on the data type and distribution. Elements include consideration of the alpha error, beta error, clinically meaningful difference, and the variability or standard deviation. The final number arrived at should be increased to include a safety...

Sample size calculation: Basic principles

Addressing a sample size is a practical issue that has to be solved during planning and designing stage of the study. The aim of any clinical research is to detect the actual difference between two groups (power) and to provide an estimate of the difference with a reasonable accuracy (precision). Hence, researchers should do a priori estimate of sample size well ahead, before conducting the stu...

Sample Size Calculation to Evaluate Mediation Analysis

Mediation analysis is used to review the comparative change in the amount of strength of association of the primary predictor with the outcome after adjustment for the mediator. Mediation models are very widely used in social sciences and biomedical sciences. Before conducting mediation studies, researchers want to know the sample size (i.e. number of subjects) required for achieving the adequa...

Sample Size Calculation of RNA-sequencing Experiment-A Simulation-Based Approach of TCGA Data

Power and sample size calculation is an essential component of experimental design in biomedical research. For RNA-sequencing experiments, sample size calculations have been proposed based on mathematical models such as Poisson and negative binomial; however, RNA-seq data has exhibited variations, i.e. over-dispersion, that has caused past calculation methods to be underor over-power. Because o...

Sample Size Calculation and Power Analysis of Time-Averaged Difference