I do not know if this has been asked before, but I do not found anything about it. My question is if anyone can provide a good reference to learn how to obtain the proportion of variance explained by each one of the fixed and random factors in a mixed-effects model.

**Answer**

I can provide some references:

Xu, R. (2003). Measuring explained variation in linear mixed effects models. *Statistics in Medicine*, **22**, 3527-3541. DOI:10.1002/sim.1572

Edwards, L. J., Muller, K. E., Wolfinger, R. D., Qaqish, B. F., & Schabenberger, O. (2008). An R2 statistic for fixed effects in the linear mixed model. *Statistics in Medicine*, **27**, 6137-6157. DOI:10.1002/sim.3429

Hössjer, O. (2008). On the coefficient of determination for mixed regression models. *Journal of Statistical Planning and Inference*, **138**, 3022-3038. DOI:10.1016/j.jspi.2007.11.010

Nakagawa, S., & Schielzeth, H. (2013). A general and simple method for obtaining R2 from generalized linear mixed-effects models. Methods in Ecology and Evolution, **4**, 133-142. DOI:10.1111/j.2041-210x.2012.00261.x

Happy reading!

**Attribution***Source : Link , Question Author : Manuel Ramón , Answer Author : Wolfgang*