Date: Wed, 1 Jun 2011 23:46:17 +1000
Reply-To: "Benjamin Spivak (Med)" <firstname.lastname@example.org>
Sender: "SPSSX(r) Discussion" <SPSSX-L@LISTSERV.UGA.EDU>
From: "Benjamin Spivak (Med)" <email@example.com>
Subject: two factor hierachical model
Hi all, this is my first post.
I am currently attempting to fit a two factor hierachical model with a
random subject effect (for nested design). However, when I run my model I
get the following message "The final hessian matrix is not positive definite
though all convergence criteria are satisfied". When I look at my estimates
of covariance parameters table, I find that my Intercept (subject) variance
is zero, with the message that my covariance parameter is redundant. If
anyone can explain what is occuring and give me some advice on how to fix
it, I would be very grateful.