Graf + Tobier are Roland Graf/ Assocreation and Nick Tobier, artists trained as architects and landscape architects and vice-versa Founded in 1997, the artist collective is based in Vienna (Austria) and Ann Arbor, Michigan (USA). Its members work anonymously on a wide range of interactive installations and urban interventions with the goal of prompting inquiry, curiosity and joy into public space through fusing physical activity and physical computing, often manipulating the ground the public walks on such as with the award winning art installation ‘bump’ (Prix Ars Electronica Distinction 2001): a set of two interactive sidewalks tangibly connecting pedestrians at two distant public spaces in real time.