This paper tells the story of how two biotechnologists used models, one working as a technologist and the other as a scientist. These stories were collected during the development of the key ideas about the nature of technology and technological knowledge during the latest curriculum development in New Zealand. Their stories of how and why they used models provided insight into the different role of modelling in technology and science. This difference can be linked to the fundamental difference between technology as a discipline that attempts to intervene in the world and create something other, and science as a discipline that attempts to explain the world. The stories illustrate the differences in the purpose, outcome and the underpinning reasoning across technology and science. We suggest that using such stories supports learning about the nature of technology and the nature of science and provides an opportunity to add a critical dimension to the development of technological literacy and scientific literacy.