An improved approximate formula is derived for determination of the sample sizes required for detecting the difference between two binomial parameters with specified type I and type II errors. Journal ...

Define statistical power List the potential consequences of doing a study that has low power, and also a study that has too much power. Explain what a type 1 and type ...

Investigator: Right, here is the data set. What is the P value? Statistician: Oh, hello again. Look, I have some concerns about how the endpoint was assessed... Investigator: Fine, I'll add a sentence ...

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 ...

For a desired power of detecting the association between a disease and several potential risk factors in case-control studies, Yang (1978, Biometrika 65, 635-640) and Halperin (1980, Biometrika 67, ...