Gagne's (1985, 2004, 2008, 2010, 2013) Differentiated Model of Giftedness and Talent (DMGT) has evolved in response to findings from the research in cognitive and developmental psychology and neuroscience. As the DMGT is commonly used in Australia, it is important that the model reflects our understanding of intelligence, what high potential is considered to be, and how high intellectual potential might be "measured" (if in fact that is the correct term). This paper will outline the development of the DMGT that has led to its current manifestation, before concluding with a recommendation on the optimal version of the model to be used by practitioners and researchers.