The link between the laboratory and learning

There is a story, perhaps apocryphal, that when a caller expressed interest in seeing his laboratory, Cavendish ordered his butler to bring it in on a tray. That was two hundred years ago, and science laboratories have grown far beyond that, encompassing whole institutions. Even in schools they are commonly large, well-equipped rooms, expensive to establish and maintain, served by specialist assistants. Despite the cost, laboratories are so embedded in the practice of science teaching it is difficult to imagine doing without them. Yet their purpose is not universally agreed, and evdence of their effect is equivocal.