Hello. Slope estimates in lme are shrinkage estimates which pull the OLS slope estimates towards the population estimates, the degree of which depends on the group sample size and the distance between the group-based estimate and the overall population estimate. Although these shrinkage estimates as said to be more precise with respect to the true values, they are also biased. So there is a tradeoff between precision and bias.
Are there rules of thumb to help determine when it is better to use the OLS slope estimates and when to use the mixed model (lme) shrinkage estimates? I have 35 groups but the numbers per group vary from over 50 to as low as 4. Thanks for any help. Bill Shipley Subject Matter Editor, Ecology North American Editor, Annals of Botany D�partement de biologie, Universit� de Sherbrooke, Sherbrooke (Qu�bec) J1K 2R1 CANADA [EMAIL PROTECTED] <http://callisto.si.usherb.ca:8080/bshipley/> http://callisto.si.usherb.ca:8080/bshipley/ [[alternative HTML version deleted]] ______________________________________________ [email protected] mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
