Dear list, I'm interested in fitting a generalized additive model in which some of the covariates are derived quantities and known measurement errors, and I am not sure how to incorporate the uncertainty of these covariates into the model fitting process. Could anyone point me towards relevant examples or documentation? Thanks in advance, Julian Julian M. Burgos Fisheries Acoustics Research Lab School of Aquatic and Fishery Science University of Washington 1122 NE Boat Street Seattle, WA 98105 Phone: 206-221-6864