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Statistical Methodology Commons

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Clinical Trials

Exact testing

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Full-Text Articles in Statistical Methodology

A Review Of Frequentist Tests For The 2x2 Binomial Trial, Chris Lloyd Dec 2014

A Review Of Frequentist Tests For The 2x2 Binomial Trial, Chris Lloyd

Chris J. Lloyd

The 2x2 binomial trial is the simplest of data structures yet its statistical analysis and the issues it raises have been debated and revisited for over 70 years. Which analysis should biomedical researchers use in applications? In this review, we consider frequentist tests only, specifically tests with control size either exactly or very close to exactly. These procedures can be classified as conditional and unconditional. Amongst tests motivated by a conditional model, Lancaster’s mid-p and Liebermeister’s test are less conservative than Fisher’s classical test, but do not control type 1 error. Within the conditional framework, only Fisher’s test can be …


On The Exact Size Of Multiple Comparison Tests, Chris Lloyd Dec 2012

On The Exact Size Of Multiple Comparison Tests, Chris Lloyd

Chris J. Lloyd

No abstract provided.


A Practical Ad-Hoc Adjustment To The Simes P-Value, Chris Lloyd Dec 2010

A Practical Ad-Hoc Adjustment To The Simes P-Value, Chris Lloyd

Chris J. Lloyd

The Simes P-value is more powerful than Bonferroni but still suffers from some conservatism when the tests are correlated. Based on a massive simulation study, I develop a formula that corrects for this conservatism. it requires the number of experimental arms which is known. It also requires the correlation and skewness of the underlying test statistics, which will need analytic approximation in practice.