. . .there are, as I see it, three major phases of good science teaching; that no teaching is likely to be optimal which does not mix all three. . .

Circle Phase -- Messing About. There is a time, much greater in amount than commonly allowed, which should be devoted to free and unguided exploratory work (call it play if you wish; I call it work). Children are given materials and equipment -- things -- and are allowed to construct, test, probe, and experiment without superimposed questions or instructions.

Triangle Phase -- Multiply Programmed . . . 'Multiply Programmed' material; material that contains written and pictorial guidance of some sort for the student, but which is designed for the greatest possible variety of topics, ordering of topics, etc. so that for almost any given way into a subject that a child may evolve on his own, there is material available that he will recognize as helping him farther along that very way.

When children have no autonomy in learning everyone is likely to be bored.

Square Phase. . . .question and answer, with discussion between children as well. . . It includes lecturing, formal or informal. I think they (theory questions) come (alive) primarily with discussion, argument, the full colloquium of children and teacher.

    by David Hawkins     in (1974). Messing about in science. The informed vision: Essays on learning and human nature.