2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/94726These short notes collect some thoughts about the way Butcher-Oemler-like and evolutionary studies are performed. We emphasize the shortcomings of several overlooked technical ingredients in the above type of studies, with the hope of making a useful cookbook for future works. We also briefly report new results of an ongoing Butcher-Oemler study at intermediate redshift.Conference proceedings: "The fabulous destiny of galaxies: Bridging past and present", Marseille, June 2005Astrophysicstext