Related Experiment Video
Updated: Jan 16, 2026

Testing Targeted Therapies in Cancer using Structural DNA Alteration Analysis and Patient-Derived Xenografts
Published on: July 25, 2020
Extending Multiple Testing With Unknown Test Dependency via the CoCo Test: With Applications to Cancer Studies
Jiangtao Gou1, Kai Wu1,2, Oliver Y Chén3,4
1Department of Mathematics and Statistics, Villanova University, Villanova, Pennsylvania, USA.
A new statistical test, the CoCo test, validates the positive dependency through stochastic ordering (PDS) condition for multiple testing. This ensures type I error rate control even with unknown dependencies between test statistics.
Area of Science:
- Statistics
- Biostatistics
- Clinical Research Methodology
Background:
- Multiple testing is prevalent in research, posing challenges for controlling type I error rates (alpha-control).
- Existing methods for alpha-control are well-established for independent tests or known joint distributions.
- Verifying the positive dependency through stochastic ordering (PDS) condition is crucial for alpha-control with unknown dependencies, yet methods are lacking.
Purpose of the Study:
- To develop a novel nonparametric statistical test for validating the PDS condition in multiple testing scenarios.
- To enable reliable alpha-control irrespective of the dependency structure between test statistics.
- To provide a practical tool for researchers facing unknown dependencies in their data.
Main Methods:
- Development of the CoCo test, a nonparametric method utilizing ranked correlation coefficients (Spearman's rho and Kendall's tau).
- The CoCo test is designed to algebraically assess the PDS condition.
- Validation through simulation studies and application to real-world meta-analyses.
Main Results:
- The CoCo test effectively detects violations or confirmations of the PDS condition.
- Simulation studies demonstrated the test's reliability in assessing dependency structures.
- Application to meta-analyses showcased its practical utility in evaluating PDS.
Conclusions:
- The CoCo test offers a robust solution for validating the PDS condition in multiple testing.
- Researchers are encouraged to assess the PDS condition when dependencies are uncertain.
- The CoCo test provides methodological and technical advancements for statistical analysis.
More Related Videos
Related Concept Videos
Cancer Survival Analysis
Multiple Comparison Tests
It would be easy to compare two samples using a significance alpha level of 0.05. In other words, there is only one sample pair to be compared. However, it would be difficult to identify a significantly different sample if the number...
Mouse Models of Cancer Study
The development of transgenic, knockout, and knock-in mice has led to an exponential increase in their use as model organisms in research,...
In-vitro Mutagenesis
Introduction to Test of Independence
The test statistic for a test of independence is similar to that of a goodness-of-fit test:
Cochran's Q Test

