EXD.4:2 - Problem
A sequence of alternating messages can leave the explanation unchanged. The explainer may treat every objection as a lack of knowledge, respond to every acknowledgement as proof of understanding, or repeat a valid account after the recipient changes the question.
Explanatory dialogue needs a constructive link between the recipient’s contribution and the next move. It also needs a stopping point. Keeping someone talking, agreeing or completing exercises is not the purpose of every explanation.