The sample size calculator allows you to calculate the required responding sample size, standard error, RSE, and a confidence interval (95% or 99%) for a proportion estimate, using just one of these ...

Sample size, namely the number of subjects that should be included in a study to reach the desired endpoint and statistical power, is a fundamental concept of scientific research. Indeed, sample size ...

Wondering how many people in the United States have a smartphone? If you poll 20 people on the street, your survey won’t be representative of the entire American population. But if you just want to ...

What is stratified random sampling? Stratified random sampling is the technique of breaking the population of interest into groups (called strata) and selecting a random sample from within each of ...

Overview: This webinar covers the statistical methods used to calculate sample sizes for both attribute and variables data. Methods for collecting the sample will be covered. Every sampling plan has ...

Using whole populations for a study is not practical nor feasible. For this reason, when performing a clinical study, a 'sample' is selected from the population and, from the obtained results, we make ...

Hi, thanks for this useful tool. I want to consult you that the process of calculation of Cochran Q value (also named HetChiSq in software). I have understood the heterogeneity calculation process in ...