How can we evaluate the child’s progress without any exams?

The Child here evaluates his or her progress. The child’s work and portfolio are normally the major source of progress tracking. Also since the child would be interacting with the world at all the times, the world may give appropriate feedback. For example somebody interested in writing would get feedback from say a newspaper or magazine, while somebody making music will get feedback from earning music mentor or music company and so on.
So using a combination of self-tracking and expert-feedbacks the child builds his or her journey. Peers, family and other well-wishers obviously are there to both pat and kick, as required.