Power analyses and sample size calculations are important parts of many research projects. Often, before data are even collected, it is necessary to calculate and justify the required sample size for ...

Yan Zhuang specializes in the areas of sequential analysis, sampling strategies, sample size determination, and statistical inference. She also enjoys working with people from other disciplines to ...

'How large a sample do I need?' is one of the most commonly asked questions of a statistician. It is also one of the hardest questions to answer. The researcher posing the query usually believes, ...