The Boondall wetlands development project seemed an ideal focus for a critical teaching experiment in a Brisbane primary school. Sixty-five students in an ungraded Years 4/5/6 classroom were introduced to the processes of critical investigation and decision making, and applied these to an extensive study of the Boondall project. Their experiences included the study of print, graphic and video materials related to the issue, a visit to the site, and discussions with consevationists and a local alderman. Eventually, groups formed according to the final decision made, and presentation of each case was planned. Throughout, special sessions encouraged students to reflect upon the nature of controversy, the process of investigation, and the quality of decision making.