At primary age, it is best if natural curiosity leads to self exploration, to whatever depth the child’s interest takes him/her. I suspect that formal supervision by the teacher, however well meaning, could dampen enthusiasm and possibly stifle progress, particularly if the teacher doesn’t actually share an interest in the subject.
In primary, my son was often given time on the classroom computers to research topics of interest. His teacher provided bare but appropriate scaffolding by suggesting a format he could use to prepare presentations for the rest of the class. He only ended up presenting a couple of these presentations but he developed a good approach to research which has since served him well.
