I need to check some code on my message about the posterior variance. I seem to have a mix of old and new objects in my workspace, and this is likely the cause of the problem. Sorry. Naomi S. Altman 814-865-3791 (voice) Associate Professor Bioinformatics Consulting Center Dept. of Statistics 814-863-7114 (fax) Penn State University 814-865-1348 (Statistics) University Park, PA 16802-2111