Originally published in 1965 Thinking in Structures, gives a full account of the experiments on the learning and understanding of structures made by the authors at the University of Adelaide. The results challenged some well-established assumptions at the time. According to Sir Frederic Bartlett in his foreword, this research effected a bold new step forward in the investigation of thinking activities and opened up a large field for further progressive investigation. Today it can be read in its historical context.