## The Annals of Statistics

### Phase transition and regularized bootstrap in large-scale $t$-tests with false discovery rate control

#### Abstract

Applying the Benjamini and Hochberg (B–H) method to multiple Student’s $t$ tests is a popular technique for gene selection in microarray data analysis. Given the nonnormality of the population, the true $p$-values of the hypothesis tests are typically unknown. Hence it is common to use the standard normal distribution $N(0,1)$, Student’s $t$ distribution $t_{n-1}$ or the bootstrap method to estimate the $p$-values. In this paper, we prove that when the population has the finite 4th moment and the dimension $m$ and the sample size $n$ satisfy $\log m=o(n^{1/3})$, the B–H method controls the false discovery rate (FDR) and the false discovery proportion (FDP) at a given level $\alpha$ asymptotically with $p$-values estimated from $N(0,1)$ or $t_{n-1}$ distribution. However, a phase transition phenomenon occurs when $\log m\geq c_{0}n^{1/3}$. In this case, the FDR and the FDP of the B–H method may be larger than $\alpha$ or even converge to one. In contrast, the bootstrap calibration is accurate for $\log m=o(n^{1/2})$ as long as the underlying distribution has the sub-Gaussian tails. However, such a light-tailed condition cannot generally be weakened. The simulation study shows that the bootstrap calibration is very conservative for the heavy tailed distributions. To solve this problem, a regularized bootstrap correction is proposed and is shown to be robust to the tails of the distributions. The simulation study shows that the regularized bootstrap method performs better than its usual counterpart.

#### Article information

Source
Ann. Statist., Volume 42, Number 5 (2014), 2003-2025.

Dates
First available in Project Euclid: 11 September 2014

Permanent link to this document
https://projecteuclid.org/euclid.aos/1410440632

Digital Object Identifier
doi:10.1214/14-AOS1249

Mathematical Reviews number (MathSciNet)
MR3262475

Zentralblatt MATH identifier
1288.53027

Subjects
Primary: 62H15: Hypothesis testing

#### Citation

Liu, Weidong; Shao, Qi-Man. Phase transition and regularized bootstrap in large-scale $t$-tests with false discovery rate control. Ann. Statist. 42 (2014), no. 5, 2003--2025. doi:10.1214/14-AOS1249. https://projecteuclid.org/euclid.aos/1410440632

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#### Supplemental materials

• Supplementary material: Supplement to “Phase transition and regularized bootstrap in large-scale $t$-tests with false discovery rate control”. The supplementary material includes part of numerical results and the proof of Lemma 6.1 and Propositions 2.1, 2.2, 2.3 and 3.1.