We would like to invite you to participate in the next seminar at the University of Sydney. Note that the venue for the seminar is Carslaw 373. ------------------------------------------------------------------------------------------------------ Empirical Saddlepoint Approximations for Stratified Random Sampling John Robinson (University of Sydney) Friday, 20 April, 2.00pm Carslaw 373 ------------------------------------------------------------------------------------------------------- To obtain confidence intervals or tests concerning a finite population mean from simple random sampling and stratified sampling, it is necessary to use Studentized statistics. Normal or Student-t approximations have been used for many years. Booth, Butler and Hall (JASA, 1994) obtained bootstrap methods for both these situations. For simple random samples, Edgeworth approximations were obtained by Sugden and Smith (JRSS B, 1998, 2000) and Dai and Robinson (SPL, 2001) obtained empirical saddlepoint approximations. We extend the work on empirical approximations to the case of stratified random sampling and note that this gives a saddlepoint approximation to the bootstrap. This is joint work with Zhishui Hu and Chunsheng Ma. --------------------------------------------------------------------------- Please visit: http://www.maths.usyd.edu.au/u/StatSeminar/ for more information about past and coming seminars. Enquiries about the Statistics Seminar: Rafal Kulik, rkuli@maths.usyd.edu.au