The ability to make effective decisions, especially under conditions of stress, is a characteristic sought by all performers. One endeavour where this is valued is sport, where time and competitive pressure invariably leads to a right or wrong decision in the final moments of the contest. Coaches have long sought effective means by which they can train their athletes to make better decisions. Decision training is perhaps the first model of coaching based on research designed to facilitate this goal. The roots of decision training are in cognitive science and motor learning. Magill (2001) states that in motor learning we ‘do not directly observe learning; we directly observe behaviour’ and further ‘we must make inferences about learning from the behaviour we observe’ (p. 168). Similarly, Schmidt and Lee (1999) state that motor learning ‘is not directly observeable . . . changes in the patterning of muscular activity are rarely directly observeable . . . and one must infer their existence from changes in motor behaviour’ (p. 265). Traditionally, the difficulty for the coach therefore, has been to infer whether the perceptual and cognitive aspects of performance have been trained on the basis of observable behaviours.