نتایج جستجو برای: repeated measures

تعداد نتایج: 446658  

Journal: :Statistics in medicine 2007
Tonya S King Vernon M Chinchilli Josep L Carrasco

The concordance correlation coefficient is commonly used to assess agreement between two raters or two methods of measuring a response when the data are measured on a continuous scale. However, the situation may arise in which repeated measurements are taken for each rater or method, e.g. longitudinal studies in clinical trials or bioassay data with subsamples. This paper proposes a coefficient...

Journal: :BJOG : an international journal of obstetrics and gynaecology 2005
David E Wright Ian Bradbury

OBJECTIVE To demonstrate the potential value of screening for Down's Syndrome using highly correlated repeated measures of serum markers taken in the first and second trimesters of pregnancy. DESIGN A Monte Carlo simulation study. POPULATION Detection rates and false positive rates relating to the maternal age distribution of England and Wales for the period 1996 to 1998 were obtained using...

Journal: :Technometrics 2013
Brian P. Weaver William Q. Meeker Luis A. Escobar Joanne Wendelberger

Repeated measures degradation studies are used to assess product or component reliability when there are few or even no failures expected during a study. Such studies are used to assess the shelf life of materials and products. We show how to evaluate the properties of proposed test plans needed to identify statistically efficient tests. We consider test plans for applications where parameters ...

2011
Vinod Kumar Prachi Mehta Gaurav Shukla

ABSTRACT In this paper, we have used SAS software for the multivariate analysis of repeated measures data due to Grizzel and Allen (1969). We have applied four multivariate methods viz MANOVA, Profile Analysis, non-parametric multisample rank sum test and non-parametric multisample median test to analyse two sets of data. The findings of the study reveal that profile analysis gives similar resu...

2013
Mario Hasler

This article addresses the problem of multiple contrast tests for repeated measures. Three procedures are described and compared by simulations concerning the familywise error type I. The procedure based on sandwich estimators seems to be most robust, except for all-pair comparisons.

2014
Laurent Mathevet Julian Romero

One of the fundamental results in repeated games is the Folk theorem, which predicts a plethora of equilibrium outcomes. Many have argued that this extreme number of equilibria is a virtue, as it can explain a variety of different behaviors. However, this result leaves us with almost no predictive power. This paper provides measures for evaluating the predictive power of a theory given experime...

2008
Peter Dixon

Accuracy is often analyzed using analysis of variance techniques in which the data are assumed to be normally distributed. However, accuracy data are discrete rather than continuous, and proportion correct are constrained to the range 0–1. Monte Carlo simulations are presented illustrating how this can lead to distortions in the pattern of means. An alternative is to analyze accuracy using logi...

2004
Geert Molenberghs Geert Verbeke GEERT VERBEKE

When choosing a parametric statistical model two important considerations are mathematical soundness and substantive relevance. In this paper, we illustrate and exemplify that a number of issues arise from these considerations, even in relatively simple settings, such as ordinal regression, linear mixed models, models for cross-classified data and generalized linear mixed models. Many of our po...

2010
Michael Friendly

Hypothesis error (HE) plots, introduced in Friendly (2007), provide graphical methods to visualize hypothesis tests in multivariate linear models, by displaying hypothesis and error covariation as ellipsoids and providing visual representations of effect size and significance. These methods are implemented in the heplots for R (Fox, Friendly, and Monette 2009a) and SAS (Friendly 2006), and appl...

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