The more tests we perform on a set of data, the more likely we are to reject the null hypothesis when it is true (i.e., a “Type I” error). This is a consequence of the logic of hypothesis testing: We reject the null hypothesis if we witness a rare event. But the larger the number of tests, the easier it is to find rare events and therefore the easier it is to make the mistake of thinking that t...

This paper considers the practical problem in animal carcinogenesis experiments where several treatment groups are compared with a control group in a one-way layout and the observed survival data are subject to random right-censorship. Proposed herein are multiple testing procedures based on two-sample weighted logrank statistics, each comparing an individual treatment with the control, for det...

We consider the problem of efficiently allocating simulation effort to determine which of several simulated systems have mean performance exceeding a known threshold. This determination is known as multiple comparisons with a control. Within a Bayesian formulation, the optimal fully sequential policy for allocating simulation effort is the solution to a dynamic program. We show that this dynami...

We consider a follow-up study in which an outcome variable is to be measured at fixed time points and covariate values are measured prior to start of follow-up. We assume that the conditional mean of the outcome given the covariates is a linear function of the covariates and is indexed by occasion-specific regression parameters. In this paper we study the asymptotic properties of several freque...

OBJECTIVE Identify racial/ethnic differences among people with multiple sclerosis (MS) in demographics, MS disease characteristics, and health services received. PARTICIPANTS We analyzed enrollment data from the Registry of the North American Research Committee on Multiple Sclerosis (NARCOMS) Project to compare 26,967 Caucasians, 715 Latinos, and 1,313 African Americans with MS. DESIGN Raci...

In this issue of the journal, Prof. Jon Wakefield provides a contribution to the complex topic of screening genetic associations. My comments here are intended to clarify some points and outline connections of his discussion to broader problems, describing how methods such as Wakefield’s can be appropriate in epidemiology beyond genetic research. I will also comment on a few aspects of his pres...

Whole genome microarray investigations (e.g. differential expression, differential methylation, ChIP-Chip) provide opportunities to test millions of features in a genome. Traditional multiple comparison procedures such as familywise error rate (FWER) controlling procedures are too conservative. Although false discovery rate (FDR) procedures have been suggested as having greater power, the contr...

Analysis of functional magnetic resonance imaging (fMRI) data typically involves over one hundred thousand independent statistical tests; therefore, it is necessary to correct for multiple comparisons to control familywise error. In a recent paper, Eklund, Nichols, and Knutsson used resting-state fMRI data to evaluate commonly employed methods to correct for multiple comparisons and reported un...

A large literature measures the allocative and technical efficiency of a set of firms using econometric techniques to estimate stochastic production frontiers or distance functions. Typically, researchers compute only the precision of individual efficiency rankings. Recently, Horrace and Schmidt (2000) have applied sampling theoretic statistical techniques known as multiple comparisons with a c...

introduction: video-assisted clinical instruction (vacid) has been found to be a beneficial teaching tool for various fields in dentistry. the aim of this interventional study was to compare the efficacy of live conventional demonstration (cd), video teaching, and vacid (video with explanation) methods in teaching of root canal treatment to undergraduate dental students. methods and materials: ...