Russell Lenth- Colloquium Speaker

Professor Emeritus
Date: 
Thursday, March 12, 2015 - 3:30pm
Colloquium Title: 
Getting the Most From Least-squares Means
Location: 
Reception at 3:00 p.m. in 241 SH / Talk at 3:30 in 61 SH

Least-squares means for a statistical model are marginal averages of predictions over a reference grid consisting of combinations of factor levels and covariate values. They can be thought of as the marginal means we would have obtained if the data had arisen from a balanced, controlled experiment. The talk focuses on the design and use of the lsmeans package for R, including examples with messy data and mixed models. Some more recent enhancements will be illustrated, including equivalence tests, mediating covariates, and ordinal responses.