In the last decades, digital technology has introduced data-driven representational and generative methodologies based on principles such as parametric definition and algorithmic processing. In this context, the fifteenth issue of Footprint examines the development of data-driven techniques such as digital drawing, modelling and simulation, with respect to their relationship to design. The data propelling these techniques may consist of qualitative or quantitative values and relations that are algorithmically processed. However, the focus here is not on each technique and its respective representational and generative aspects, but on the interface between these techniques and design conceptualisation.