The effect of different seating positions on the frequency with which pupils were addressed questions by the teacher was examined in two primary school classes. Baseline observations identified areas in both classes to which a disproportionately high and low number of questions were directed. Utilising a multiple baseline design six pupils in both classes were systematically moved in and out of these areas. Results indicate that location within the classroom is in itself a causal factor in the question distribution pattern. Concomitant measures of teacher location and pupil on-task levels indicate that changes in these features of the behavioural ecology of the classes did not confound the location effects. Data are discussed illustrating the value of obtaining observational measures on behaviours concomitant with the dependent variable both in order to monitor uncontrolled variables which it is anticipated may confound the experimental effects, and to assist in the identification of other potentially significant ecological setting events within the classroom.