RE: Linear VS LTBS

Hi Neil, 1. When data are log-transformed the $ERROR block has to change: additive error becomes true exponential error which cannot be achieved without log-transformation (Nick, correct me if I am wrong). 2. Error cannot "go away". You claim your structural model (THs) remained unchanged. Therefore the "amount" of error will remain the same as well. If you reduce BSV you may have to "pay" for it with increased residual variability. 3. Confidence intervals of ETAs based on standard errors produced during the covariance step are unreliable (many threads in NMusers). Do bootstrap to obtain more reliable C.I.. These are my five cents worth of thought in the early morning, Good luck, Joachim -------------------------------------------------------------------------- AstraZeneca UK Limited is a company incorporated in England and Wales with registered number: 03674842 and a registered office at 15 Stanhope Gate, London W1K 1LN. Confidentiality Notice: This message is private and may contain confidential, proprietary and legally privileged information. If you have received this message in error, please notify us and remove it from your system and note that you must not copy, distribute or take any action in reliance on it. Any unauthorised use or disclosure of the contents of this message is not permitted and may be unlawful. Disclaimer: Email messages may be subject to delays, interception, non-delivery and unauthorised alterations. Therefore, information expressed in this message is not given or endorsed by AstraZeneca UK Limited unless otherwise notified by an authorised representative independent of this message. No contractual relationship is created by this message by any person unless specifically indicated by agreement in writing other than email. Monitoring: AstraZeneca UK Limited may monitor email traffic data and content for the purposes of the prevention and detection of crime, ensuring the security of our computer systems and checking Compliance with our Code of Conduct and Policies.