Hi all, not to invent the wheel a second time I wonder if someone out there has programmend Snee's CADEX algorithm (Validation of regression models: Methods and examples, Technometrics 19, 415-428). Thank you in advance. D. Trenkler -- Dietrich Trenkler c/o Universitaet Osnabrueck Rolandstr. 8; D-49069 Osnabrueck, Germany email: Dietrich.Trenkler at Uni-Osnabrueck.de