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Documents 62J15 5 résultats

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I shall classify current approaches to multiple inferences according to goals, and discuss the basic approaches being used. I shall then highlight a few challenges that await our attention : some are simple inequalities, others arise in particular applications.

62J15 ; 62P10

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Selective inference in genetics - Sabatti, Chiara (Auteur de la Conférence) | CIRM H

Multi angle

Geneticists have always been aware that, when looking for signal across the entire genome, one has to be very careful to avoid false discoveries. Contemporary studies often involve a very large number of traits, increasing the challenges of "looking every-where". I will discuss novel approaches that allow an adaptive exploration of the data, while guaranteeing reproducible results.

62F15 ; 62J15 ; 62P10 ; 92D10

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Post hoc bounds on false positives using reference families - Neuvial, Pierre (Auteur de la Conférence) | CIRM H

Virtualconference

We present confidence bounds on the false positives contained in subsets of selected null hypotheses. As the coverage probability holds simultaneously over all possible subsets, these bounds can be applied to an arbitrary number of possibly datadriven subsets.
These bounds are built via a two-step approach. First, build a family of candidate rejection subsets together with associated bounds, holding uniformly on the number of false positives they contain (call this a reference family). Then, interpolate from this reference family to find a bound valid for any subset.
This general program is exemplified for two particular types of reference families: (i) when the bounds are fixed and the subsets are p-value level sets (ii) when the subsets are fixed, spatially structured and the bounds are estimated.[-]
We present confidence bounds on the false positives contained in subsets of selected null hypotheses. As the coverage probability holds simultaneously over all possible subsets, these bounds can be applied to an arbitrary number of possibly datadriven subsets.
These bounds are built via a two-step approach. First, build a family of candidate rejection subsets together with associated bounds, holding uniformly on the number of false positives ...[+]

62J15

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The highly influential two-group model in testing a large number of statistical hypotheses assumes that the test statistics are drawn independently from a mixture of a high probability null distribution and a low probability alternative. Optimal control of the marginal false discovery rate (mFDR), in the sense that it provides maximal power (expected true discoveries) subject to mFDR control, is known to be achieved by thresholding the local false discovery rate (locFDR), i.e., the probability of the hypothesis being null given the set of test statistics, with a fixed threshold.
We address the challenge of controlling optimally the popular false discovery rate (FDR) or positive FDR (pFDR) rather than mFDR in the general two-group model, which also allows for dependence between the test statistics. These criteria are less conservative than the mFDR criterion, so they make more rejections in expectation.
We derive their optimal multiple testing (OMT) policies, which turn out to be thresholding the locFDR with a threshold that is a function of the entire set of statistics. We develop an efficient algorithm for finding these policies, and use it for problems with thousands of hypotheses. We illustrate these procedures on gene expression studies. [-]
The highly influential two-group model in testing a large number of statistical hypotheses assumes that the test statistics are drawn independently from a mixture of a high probability null distribution and a low probability alternative. Optimal control of the marginal false discovery rate (mFDR), in the sense that it provides maximal power (expected true discoveries) subject to mFDR control, is known to be achieved by thresholding the local ...[+]

62F03 ; 62J15 ; 62P10

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Optimal and maximin procedures for multiple testing problems - Rosset, Saharon (Auteur de la Conférence) | CIRM H

Virtualconference

Multiple testing problems are a staple of modern statistics. The fundamental objective is to reject as many false null hypotheses as possible, subject to controlling an overall measure of false discovery, like family-wise error rate (FWER) or false discovery rate (FDR). We formulate multiple testing of simple hypotheses as an infinite-dimensional optimization problem, seeking the most powerful rejection policy which guarantees strong control of the selected measure. We show that for exchangeable hypotheses, for FWER or FDR and relevant notions of power, these problems lead to infinite programs that can provably be solved. We explore maximin rules for complex alternatives, and show they can be found in practice, leading to improved practical procedures compared to existing alternatives. We derive explicit optimal tests for FWER or FDR control for three independent normal means. We find that the power gain over natural competitors is substantial in all settings examined. We apply our optimal maximin rule to subgroup analyses in systematic reviews from the Cochrane library, leading to an increased number of findings compared to existing alternatives.[-]
Multiple testing problems are a staple of modern statistics. The fundamental objective is to reject as many false null hypotheses as possible, subject to controlling an overall measure of false discovery, like family-wise error rate (FWER) or false discovery rate (FDR). We formulate multiple testing of simple hypotheses as an infinite-dimensional optimization problem, seeking the most powerful rejection policy which guarantees strong control of ...[+]

62F03 ; 62J15 ; 62P10

Sélection Signaler une erreur