Most professions choose their best practices through a form of natural selection and evolution. Rookies try all the different ways and 30 years later they are V

Most professions choose their best practices through a form of natural selection and evolution. Rookies try all the different ways and 30 years later they are Veterans. The Veteran then passes on the best ways he learned to the Rookies, who copy it, and then over the course of their career slowly improve on it as well. Even the most "simple" task like scaffolding (for instance) has heaps of "craft" in it. What research team decided that scaffolders should thread scaffold clamps between their fingers when they carry them? There is a subtle technique to this that has been passed down through generations. This is how all professions learn the tricks of their trade. People try stuff, figure out what works best for them personally, and then pass that knowledge down to the rookies. Certainly with programming this happens at university - I've had profs who give practical advice like, "Make sure your program is always capable of compiling throughout the entire dev process." This is folk knowledge yes, but it's practical folk knowledge that HAS been tested over the course of careers by many people. It is not economical to have many dedicated research scientists trying to figure out these things. They are figured out by people as they do their job. The most important thing is mentoring. Paul Graham widely shares the things he has learned from experience and those things HAVE been legitimately tested because he has tried ways that failed and tried ways that succeeded. Just because it is not double blind does not mean that it hasn't been tested.