A critical point in investigative work: Defining variables

This article reports research concerning the definition of variables by pupils aged 12 to 14 during investigative work. The findings suggest that an increase in the complexity of an investigation lowers the ability to identify relevant variables as pupils start to lose track of the whole task. Substantive concepts intrude most obviously on the ability to define the appropriate dependent variable and to control variables. Pupils appear to have difficulty in realizing the advantages of defining the independent variable as continuous for the investigation as a whole. Possible explanations are considered and some practical ways of addressing this point of difficulty are put forward.