Boiled eggs

This recipe gives instructions for something very simple, a boiled egg. They instruct you to put the eggs into cold water, bring them to a boil, and then boil for four minutes. However, there were no instructions for identifying the moment when the water was boiling. This vagueness would probably be frustrating for a child (and many adults). We started timing when the water wasn't quite boiling, but re-started once it was clearly at a boil. I was surprised that the eggs were not over-cooked.