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Subsampling estimates of the Lasso distribution.

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6.1 Low dimensinal setting 59<br />

Figure 6.2: <strong>Subsampling</strong> confidence intervals for single scenarios <strong>of</strong> <strong>the</strong> models B and B’<br />

(n= 250). Red triangles stand for <strong>the</strong> true parameters.<br />

at least one false rejection. This is formalized by <strong>the</strong> Family Wise Error Rate (FEWR)<br />

defined as follows<br />

Definition 6.1.3.1. Let H 1 , · · · , H s be a family <strong>of</strong> hypo<strong>the</strong>ses. The corresponding FWER<br />

is defined as <strong>the</strong> probability to make at least one false rejection among <strong>the</strong> hypo<strong>the</strong>ses H i ,<br />

i.e.<br />

( s<br />

)<br />

⋃<br />

F W ER = P H1 ,...,H s<br />

{H i is rejected }<br />

i=1<br />

(6.1.3.1)<br />

Our goal is to test <strong>the</strong> hypo<strong>the</strong>ses H 1 , . . . , H s while controling <strong>the</strong> FWER to a given level<br />

α. That is,<br />

F W ER ≤ α.<br />

We focus on <strong>the</strong> Bonferonni-Holm procedure. It is a so called step-down procedure based<br />

on p-values for individual hypo<strong>the</strong>ses. We recall <strong>the</strong> definition <strong>of</strong> a p-value,

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