Isobel, in an earlier reply you mentioned Sichel's t estimator and a paper of yours discussing it. I downloaded it, but hélas, addendum 2 which apparently is about Sichel's t is missing. (Sichel's original paper from 1952 is a bit difficult to get.)
Can you help ? Or does anybody know any (accessible) references on Sichel's t ? Thanks, Peter 31 December 2006 01:07:24 From: Isobel Clark <[EMAIL PROTECTED]> (...) >Sichel expanded on this by showing that estimates of mu and sigma >calculated from the logarithm of the samples may be substituted for mu >and sigma in the above equation. If you have enough samples (more than >40) this will provide a better estimator for the lognormal mean. Better >means: maximum likelihood, more efficient, 'closer to reality', with >narrower confidence bounds. These bounds will not be symmetrical, as in >the Normal or CLT case. No amount of sampling is sufficient to make that >happen. > >If you have less than 40 samples, the above formula gives a biassed >estimate (and confidence bounds). Sichel provided tables to correct this >bias and calculate the confidence bounds. If you do not have access to >Sichel or Finney's work, you might find my 1987 SAIMM paper useful. It >can be downloaded by following the publications link at [ >http://uk.geocities.com/drisobelclark/resume >]http://uk.geocities.com/drisobelclark/resume (...) ----------------------------------------------------- Peter Bossew European Commission (EC) Joint Research Centre (JRC) Institute for Environment and Sustainability (IES) TP 441, Via Fermi 1 21020 Ispra (VA) ITALY Tel. +39 0332 78 9109 Fax. +39 0332 78 5466 Email: [EMAIL PROTECTED] WWW: http://rem.jrc.cec.eu.int "The views expressed are purely those of the writer and may not in any circumstances be regarded as stating an official position of the European Commission." + + To post a message to the list, send it to ai-geostats@jrc.it + To unsubscribe, send email to majordomo@ jrc.it with no subject and "unsubscribe ai-geostats" in the message body. DO NOT SEND Subscribe/Unsubscribe requests to the list + As a general service to list users, please remember to post a summary of any useful responses to your questions. + Support to the forum can be found at http://www.ai-geostats.org/
