Liu, Guanfu; Fu, Yuejiao; Li, Pengfei; Pu, Xiaolong Using differential variability to increase the power of the homogeneity test in a two-sample problem. (English) Zbl 1382.62055 Stat. Sin. 28, No. 1, 27-41 (2018). Summary: We consider a two-sample homogeneity testing problem often encountered in case-control studies with contaminated controls, or in detecting a treatment effect when some subjects are not affected by the treatment in biological experiments. We propose an EM-test designed to simultaneously detect mean difference and differential variability in the two samples. We show that the EM-test statistic has a chi-squared null limiting distribution. The asymptotic properties of the EM-test under local alternatives are also investigated, and sample-size calculation is given. The main results are established for general location-scale family of distributions. Simulation results show that the EM-test outperforms existing methods, and two data examples are used to illustrate the application of the proposed method. Cited in 5 Documents MSC: 62P10 Applications of statistics to biology and medical sciences; meta analysis Keywords:differential variability; EM-test; homogeneity test; limiting distribution; local power; mixture model; two-sample problem PDFBibTeX XMLCite \textit{G. Liu} et al., Stat. Sin. 28, No. 1, 27--41 (2018; Zbl 1382.62055) Full Text: DOI Link