Hostname: page-component-586b7cd67f-tf8b9 Total loading time: 0 Render date: 2024-11-22T02:29:51.910Z Has data issue: false hasContentIssue false

OPTIMAL SELECTION OF THE k-TH BEST CANDIDATE

Published online by Cambridge University Press:  10 April 2019

Yi-Shen Lin
Affiliation:
Institute of Statistical Science, Academia Sinica, Taipei 115 Taiwan, R.O.C E-mail: [email protected]
Shoou-Ren Hsiau
Affiliation:
Department of Mathematics, National Changhua University of Education, No. 1, Jin-De Rd., Changhua 500 Taiwan, R.O.C. E-mail: [email protected]
Yi-Ching Yao
Affiliation:
Institute of Statistical Science, Academia Sinica, Taipei 115 Taiwan, R.O.C. E-mail: [email protected]

Abstract

In the subject of optimal stopping, the classical secretary problem is concerned with optimally selecting the best of n candidates when their relative ranks are observed sequentially. This problem has been extended to optimally selecting the kth best candidate for k ≥ 2. While the optimal stopping rule for k=1,2 (and all n ≥ 2) is known to be of threshold type (involving one threshold), we solve the case k=3 (and all n ≥ 3) by deriving an explicit optimal stopping rule that involves two thresholds. We also prove several inequalities for p(k, n), the maximum probability of selecting the k-th best of n candidates. It is shown that (i) p(1, n) = p(n, n) > p(k, n) for 1<k<n, (ii) p(k, n) ≥ p(k, n + 1), (iii) p(k, n) ≥ p(k + 1, n + 1) and (iv) p(k, ∞): = lim n→∞p(k, n) is decreasing in k.

Type
Research Article
Copyright
Copyright © Cambridge University Press 2019 

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

1Chow, Y.-S., Robbins, H., & Siegmund, D. (1971). Great expectations: the theory of optimal stopping. Boston, MA: Houghton Mifflin.Google Scholar
2Ferguson, T.S. (1989). Who solved the secretary problem? Statistical Science 4: 282296.Google Scholar
3Ferguson, T.S. (2008). Optimal stopping and applications. Mathematics Department, UCLA, http://www.math.ucla.edu/~tom/Stopping/Contents.html.Google Scholar
4Freeman, P.R. (1983). The secretary problem and its extensions: a review. International Statistical Review 51: 189206.Google Scholar
5Graham, R., Knuth, D., & Patashnik, O. (1994). Concrete mathematics: a foundation for computer science. Reading, MA: Addison-Wesley Publishing Company.Google Scholar
6Lindley, D.V. (1961). Dynamic programming and decision theory. Applied Statistics 10: 3951.Google Scholar
7Rose, J.S. (1982). A problem of optimal choice and assignment. Operational Research 30: 172181.Google Scholar
8Rose, J.S. (1982). Selection of nonextremal candidates from a sequence. Journal of Optimization Theory and Application 38: 207219.Google Scholar
9Samuels, S.M. (1991). Secretary problems. In Ghosh, B.K. and Sen, P.K. (eds.), Handbook of sequential analysis, (Statistics Textbooks Monographs, Vol. 118), New York: Marcel Dekker, pp. 381405.Google Scholar
10Suchwalko, A. & Szajowski, K. (2002). Non standard, no information secretary problems. Scientiae Mathematicae Japonicae 56: 443456.Google Scholar
11Szajowski, K. (1982). Optimal choice problem of a-th object. Mat. Stos 19: 5165 (in Polish).Google Scholar
12Vanderbei, R.J. (2012). The postdoc variant of the secretary problem. Technical Report. http://www.princeton.edu/~rvdb/tex/PostdocProblem/PostdocProb.pdf.Google Scholar