Re: Question: Number of ETA and EPS in statistic significance

Date: Wed, 26 May 1999 08:42:05 +0200 From: Mats Karlsson <Mats.Karlsson@biof.uu.se> Subject: Re: Question: Number of ETA and EPS in statistic significance Dear Takeshi, As I understand it, the same test can be performed for ETA and EPS. However, there are two things to keep in mind. 1) The test is approximate for THETA and even more so for variance components. As the information in data increase, the test statistics for variance components are converging towards the true slower than for THETA. 2) Even for THETA's, the test can behave badly even under relatively normal situations. Using simulations, we have compared nominal to true p-levels and found that the true p-level for 3.84 sometimes can be >0.4, and that several foctors influence the difference between the nominal and true p-levels. A presentation on this topic will be given by Ulrika Wahlby at the upcoming PAGE meeting (Saintes, France June 17-18). For ETA's and EPS's we have not yet generated the same information. Best regards, Mats Karlsson ________________________________________________________ Mats Karlsson, PhD Uppsala University Div. of Biopharmaceutics and Pharmacokinetics Dept. of Pharmacy/ Box 580, SE-751 23 Uppsala, Sweden Internet: mats.karlsson@biof.uu.se Phone: +46 18 471 41 05 Fax: +46 18 471 40 03