Professor Hans-Peter Piepho from the Biostatistics Unit, Institute of Crop Science, University of Hohenheim, Germany presents A Coefficient of Determination (R2) for Generalized Linear Mixed Models.

Extensions of linear models are very commonly used in the analysis of biological data. Whereas goodness of fit measures such as the coefficient of determination (R²) or the adjusted R² are well established for linear models, it is not obvious how such measures should be defined for generalized linear and mixed models. There are by now several proposals but no consensus has yet emerged as to the best unified approach in these settings. In particular, it is an open question how to best account for heteroscedasticity and for covariance among observations present in residual error or induced by random effects. This talk proposes a new approach that addresses this issue and is universally applicable for arbitrary variance-covariance structures including spatial models and repeated measures. It is exemplified using three biological examples. I will also make a connection with the closely related problem of assessing heritability in breeding and quantitative genetics.

Seminars held fortnightly from 2-3pm on Mondays at various locations, light refreshments will follow.

All are welcome to attend.