ABSTRACT
The term 'bug' appears to be applied to both microbes and insects as 'nasty, creepy things'. Some of Nagy's children drew scenes of dirty places or sick-rooms to represent germs and they spoke of dust, dirt and poison. In a brainstorming exercise Wallace5 found that the words connected with disease and insanitary conditions were strongly associated with the notion of microbes by 11-and 12-year-olds, whereas 12and 13-year-olds gave fewer such instances and included more specific references to very small size, fungi, bacteria and food making. (The latter may have been due to teaching received six months previously.) Maxted's 12-and 13-year-olds mostly suggested that germs are microscopically small, light and floating in the air. Some referred to different shapes and sizes. They mentioned a range of places where bacteria occur but only two pupils referred to a living host. All these children said that bacteria are living but, although some could recall some characteristics of life taught in the previous year's lessons, none could satisfactorily use these as criteria to define the characteristics of bacterial life. Difficulties in explaining colony size revealed that pupils possessed ideas about growth which differ from the scientific concept.
