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The Gaussian approximation for multi-color generalized Friedman’s urn model

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Abstract

The generalized Friedman’s urn model is a popular urn model which is widely used in many disciplines. In particular, it is extensively used in treatment allocation schemes in clinical trials. In this paper, we show that both the urn composition process and the allocation proportion process can be approximated by a multi-dimensional Gaussian process almost surely for a multi-color generalized Friedman’s urn model with both homogeneous and non-homogeneous generating matrices. The Gaussian process is a solution of a stochastic differential equation. This Gaussian approximation is important for the understanding of the behavior of the urn process and is also useful for statistical inferences. As an application, we obtain the asymptotic properties including the asymptotic normality and the law of the iterated logarithm for a multi-color generalized Friedman’s urn model as well as the randomized-play-the-winner rule as a special case.

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References

  1. Johnson N L, Kotz S. Urn Models and Their Applications. New York: Wiley, 1977

    Google Scholar 

  2. Kotz S, Balakrishnan N. Advances in urn models during the past two decades. In: Advances in Combinatorial Methods and Applications to Probability and Statistics. Balakrishnan N, eds. Boston: Birkhäuser, 1997

    Google Scholar 

  3. Hu F, Rosenberger W F. Optimality, variability, power: Evaluating response-adaptive randomization procedures for treatment comparisons. J Amer Statist Assoc, 98: 671–678 (2003)

    Article  MATH  MathSciNet  Google Scholar 

  4. Wei L J, Durham S. The randomized pay-the-winner rule in medical trials. J Amer Statist Assoc, 73: 840–843 (1978)

    Article  MATH  Google Scholar 

  5. Wei L J. The generalized Pólya’s urn design for sequential medical trials. Ann Statist, 7: 291–296 (1979)

    Article  MATH  Google Scholar 

  6. Flournoy N, Rosenberger W F. Adaptive Designs. Hayward, CA: Institute of Mathematical Statistics, 1995

    MATH  Google Scholar 

  7. Rosenberger W F. New directions in adaptive designs. Statist Sci, 11: 137–149 (1996)

    Article  Google Scholar 

  8. Bai Z D, Hu F. Asymptotic theorem for urn models with nonhomogeneous generating matrices. Stochastic Process Appl, 80: 87–101 (1999)

    Article  MATH  MathSciNet  Google Scholar 

  9. Bai Z D, Hu F. Asymptotics in randomized urn models. Ann Appl Probab, 15: 914–940 (2005)

    Article  MATH  MathSciNet  Google Scholar 

  10. Hu F, Rosenberger W F. The Theory of Response-Adaptive Randomization in Clinical Trials. New York: John Wiley and Sons Inc, 2006

    Book  MATH  Google Scholar 

  11. Andersen J, Faries D, Tamura R N. Randomized play-the-winner design for multi-arm clinical trials. Comm Statist Theory and Methods, 23: 309–323 (1994)

    Article  MATH  Google Scholar 

  12. Hu F, Rosenberger W F. Analysis of time trends in adaptive designs with application to a neurophysiology experiment. Statist Med, 19: 2067–2075 (2000)

    Article  Google Scholar 

  13. Bai Z D, Hu F, Shen L. An adaptive design for multi-arm clinical trials. J Multivariate Anal, 81: 1–18 (2002)

    Article  MATH  MathSciNet  Google Scholar 

  14. Athreya K B, Karlin S. Limit theorems for the split times of branching processes. J Math Mech, 17: 257–277 (1967)

    MATH  MathSciNet  Google Scholar 

  15. Athreya K B, Karlin S. Embedding of urn schemes into continuous time branching processes and related limit theorems. Ann Math Statist, 39: 1801–1817 (1968)

    Article  MATH  MathSciNet  Google Scholar 

  16. Janson S. Functional limit theorems for multitype branching processes and generalized Pólya urns. Stochastic Process Appl, 110: 177–245 (2004)

    Article  MathSciNet  Google Scholar 

  17. Bai Z D, Hu F, Rosenberger W F. Asymptotic properties of adaptive designs for clinical trials with delayed response. Ann Statist, 30: 122–139 (2002)

    Article  MATH  MathSciNet  Google Scholar 

  18. Hu F, Zhang L X. The asymptotic normality of urn models for clinical trials with delayed response. Bernoulli, 10: 447–463 (2004)

    Article  MATH  MathSciNet  Google Scholar 

  19. Bai Z D, Hu F, Zhang L X. The Gaussian approximation theorems for urn models and their applications. Ann Appl Probab, 12: 1149–1173 (2002)

    Article  MATH  MathSciNet  Google Scholar 

  20. Tymofyeyev Y, Rosenberger W F, Hu F. Implementing optimal allocation in sequential binary response experiments. J Amer Statist Assoc, 102: 224–234 (2007)

    Article  MATH  MathSciNet  Google Scholar 

  21. Zhang L X, Hu F, Cheung S H. Asymptotic theorems of sequential estimation-adjusted urn models. Ann Appl Probab, 16: 340–369 (2006)

    Article  MATH  MathSciNet  Google Scholar 

  22. Ivanova A. A play-the-winner type urn model with reduced variability. Metrika, 58: 1–13 (2003)

    MATH  MathSciNet  Google Scholar 

  23. Zhang L X, Chan W S, Cheung S H, et al. A generalized urn model for clinical trials with delayed responses. Statist Sinica, 17: 387–409 (2007)

    MATH  MathSciNet  Google Scholar 

  24. Hu F, Zhang L X, Cheung S H, et al. Doubly adaptive biased coin designs with delayed responses. Canad J Statist, 36: 541–559 (2008)

    Article  MATH  MathSciNet  Google Scholar 

  25. Hu F, Zhang L X. Asymptotic properties of doubly adaptive biased coin designs for multi-treatment clinical trials. Ann Statist, 32: 268–301 (2004)

    MATH  MathSciNet  Google Scholar 

  26. Zhang L X. Strong approximations of martingale vectors and its applications in Markov-Chain adaptive designs. Acta Math Appl Sin Engl Ser, 20(2): 337–352 (2004)

    Article  MATH  MathSciNet  Google Scholar 

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Correspondence to LiXin Zhang.

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Dedicated to Professor Zhidong Bai on the occasion of his 65th birthday

This work was supported by National Natural Science Foundation of China (Grant No. 10771192) and National Science Foundation of USA (Grant No. DMS-0349048)

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Zhang, L., Hu, F. The Gaussian approximation for multi-color generalized Friedman’s urn model. Sci. China Ser. A-Math. 52, 1305–1326 (2009). https://doi.org/10.1007/s11425-009-0092-9

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  • DOI: https://doi.org/10.1007/s11425-009-0092-9

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