Ian Jamieson, a national adviser on 5-14 science, said teachers used too many groups. "The result is the teacher has a flaky in the corner while the kids just love the pandemonium. I don't know of any juggler who starts off with eight balls in the air at the same time," Mr Jamieson said.
In the wake of National Science Week, Mr Jamieson, a lecturer in biology at Jordanhill, urged schools to "adopt a scientist" as one way of enthusing pupils. "Kids are like bloodhounds when you let them loose on gathering information. They'll discover someone had three pimples and a boil."
Science was often based on theories not "right answers", Mr Jamieson said, and teachers must be prepared to explore pupils' conceptions. "I have no idea, for example, whether red hair is lighter or heavier than blond hair but I am prepared to accept it as a theory and test it out."
Mr Jamieson stressed that teachers had to set up structures to generate ideas and test hypotheses. But primaries should realise that resources for science can be kept simple.
"I am not saying there is no place for the microscope in primary schools, but you don't need the full paraphernalia of round-bottomed flasks and square-bottomed flasks," Mr Jamieson said. He had seen some excellent work on "pushing and pulling" with a brick, an elastic band, some sand and a board.
It was also important to link science to work in other subjects. "I know people who teach the Victorians or the Industrial Revolution or the Second World War without mentioning science once," he said.