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Full-Text Articles in Physical Sciences and Mathematics
A Review Of Frequentist Tests For The 2x2 Binomial Trial, Chris Lloyd
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 …
Importance Accelerated Robbins-Monro Recursion With Applications To Parametric Confidence Limits, Zdravjko I. Botev, Chris Lloyd
Importance Accelerated Robbins-Monro Recursion With Applications To Parametric Confidence Limits, Zdravjko I. Botev, Chris Lloyd
Chris J. Lloyd
Monro (1951) to calculating confidence limits leads to poor efficiency and difficulties in estimating the appropriate governing constants as well as the standard error. We suggest sampling instead from an alternative importance distribu- tion and modifying the Robbins-Monro recursion accordingly. This can reduce the asymptotic variance by the usual importance sampling factor. It also allows the standard error and optimal step length to be estimated from the simulation. The methodology is applied to computing almost exact confidence limits in a generalised linear model.
On The Exact Size Of Multiple Comparison Tests, Chris Lloyd
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
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.