Based on decades of experiences, it appears to me that every time an effective informal process becomes formalized and evaluated, it then becomes restricted, loses power and loses effectiveness.
I think it w/b useful for educators and trainers to define what informal learning processes are used, and why they're used/preferred, only if the intent of the evaluation is to improve formal learning processes.
As soon as you formalize the evaluation of informal learning, it's no longer informal.
Christie Mason