Non-linear growth models PreviousNext
Mplus Discussion > Growth Modeling of Longitudinal Data >
 Jon Heron posted on Thursday, May 12, 2016 - 5:14 am
Dear Bengt/Linda

we are currently experimenting with some non-linear growth models (specifically exponential decay) in which a Taylor series approximation is used to linearize the target function with respect to the random effects (here intercept, asymptote and half-life).

According the Preacher + Hancock's 2015 paper in Psych methods ( these models are Population Averaged (PA) such that individual trajectories do not necessarily follow the same functional form as the mean-trend.

We have recently be exploring some strange outliers by exporting the factor scores and plugging values into our exponential target function. In doing so we have produced estimated trajectories that look nothing like those produced by the software.

If this is not merely a short-coming of factor scores and is due to the afore-mentioned PA issue, then how might Mplus be generating its estimated curves if it is not merely plugging values into the target function?

many thanks, Jon
 Bengt O. Muthen posted on Friday, May 13, 2016 - 1:44 pm
You might want to look at Grimm's work - we have papers by him on our website. I don't know how factor scores function with Taylor series linearization approaches.
Back to top
Add Your Message Here
Username: Posting Information:
This is a private posting area. Only registered users and moderators may post messages here.
Options: Enable HTML code in message
Automatically activate URLs in message