Back to problem solving. The more complex and open ended a problem is, the more experience matters. I could read a book about how to be an excellent public speaker, but without practice all that knowledge about public speaking won’t be much help behind a podium.
From a training perspective, the important thing to remember is that experience can be simulated. Experience solving problems in the classroom counts in the real world.
How good a substitute simulated experience is depends on how well the problem solving domain can be simulated in the classroom, at least in the ways that matter. If you were simulating how to ask clients high value questions, it probably doesn’t matter if the classroom looks like an actual client office, but it certainly matters whether or not the “client” responds realistically. One of my mentors calls this favoring cognitive fidelity over physical fidelity.
Another kind of substitute for experience is vicarious: reading a case study, for instance, describing how someone else solved a problem (including, ideally, failures). While generally not as impactful as successfully solving a problem yourself, reading about or watching others solve problems is a quick way to build a case library in your head, and you may be exposed to strategies that may not have occurred to you on your own.
In domains where real world experience is rare, expensive, or dangerous, such as stopping a nuclear plant from melting down, simulated and vicarious experience has to be good enough that you succeed the first time when you encounter the problem in the real world. In most situations, though, the optimal blend of real, simulated, and vicarious experience depends on the costs associated with making real world mistakes and the availability of real world mentors to provide coaching and feedback. In a true apprenticeship culture, experience may all come from the real world and none from the classroom.
From an instructional design perspective, the key is to be thoughtful about where learners are gaining the experience they need to solve complex problems.