lavaan – a user-friendly SEM package for R

Remember when we pondered about an Mplus-style interface for SEM packages in R? Turns out that Yves Rosseel not only had the same idea, but did actually implement such a package first on top of the sem-package and finally as a standalone library. Lavaan is still in beta but offers a very simple syntax similar to Mplus and most of the features you might need in your daily SEM practice, including multiple estimators, FIML for missing data, multiple group comparisons and longitudinal modeling. It does not have all the cutting edge features of Mplus and its add-ons but is extremely user-friendly.

Especially notable is the super-simple implementation of multi-group and invariance testing which is way better than in Mplus and even easier than the wizard-thing in AMOS. Since measurement equivalence seems to be a hot topic nowadays in many social science applications, Yves’ ideas and implementation are very timely and useful. I am pretty sure we will add lavaan as a third option for our beginners and longitudinal workshops in the coming season (workshops are on hiatus until Jens and I have finished our PhD theses, by the way).

I have only run a few models yet but it seems like Lavaan is easier to use while OpenMX seems to support more advanced modeling, especially if you want to customize your SEM models or run simulations. Choice is good and both package will have a strong impact on the commercial offerings that have dominated the SEM market for a long time.

Thanks, Yves, for a great package, and kudos to Alexander Robitzsch for sending us the link!

London: Short Course in Factor Analysis and SEM using Stata and Mplus

Need a good reason for a trip to London in February? The London School of Hygiene & Tropical Medicine offers a 3-day workshop on CFA and SEM for social scientists and epidemiologists.

The course is held 17 – 19 February 2010 and taught by Bianca De Stavola and George Ploubidis.

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OpenMx – advanced structural equation modeling in R

A team from the University of Virginia has started to port the classic mx program to R and provide us with a powerful new SEM tool:

OpenMx is free and open source software for use with R that allows estimation of a wide variety of advanced multivariate statistical models.

The closed beta started yesterday and will open in a few months.

This is certainly great news for the SEM community and I look forward to trying it. The only thing that bugs me in all free SEM programs, including mx and John Fox’s sem package for R, is the verbose and ugly syntax for specifying models. Some oldschool LISREL users might find matrix notation easy to use, but the rest of us have been spoilt by the wonderfully concise Mplus. Jens and I did at one point plan to implement Mplus syntax on top of the sem package but I bet the OpenMx folks will beat us there!

See the excellent OpenMx homepage for details (and please vote for Mplus parsing!!)