In structural equation modelling, we are typically proposing theoretical causes of observed phenomena. These are termed "latent" (the unobserved causes) and manifest (the observed variables we measure, otherwise known as data).Importantly, the theoretical causes of behavior need not have a structure remotely resembling the correlations observed in the data. ... [Read more...]

Often in SEM scripts you will see matrices being pre- and post-multiplied by some other matrix. For instance, this figures in scripts computing the genetic correlation between variables. How does pre- and post-multiplying a variance... [Read more...]

In this post, I made an SEM model and showed the results in a table.It’s a great feature of SEM that you can sketch your ideas about how the world works, and being able to get such a sketch back out of OpenMx is very helpful.Importantly, a ... [Read more...]

Joel Caldwell gave an example of Confirmatory factor analysis in lavaan. The purpose of this post is to show you how to express this model in OpenMx. The data being modeled are in an object called ratings (see below for the code to create this object as described here. Here’... [Read more...]