A method of enabling user interaction with computer software running in a computer system. The includes generating coded data indicative of at least one interactive element, determining a page description defining a layout of information and coded data relating to the computer software, and printing an interface surface using the page description. The interface surface is then used to allow a sensing device to sense some of the coded data when placed in an operative position relative to the interface surface. The sensing device generates indicating data indicative of a user identity stored in the sensing device and the interactive element. The indicating data is then transferred to the computer system which uses the indicating data and the page description to determine instructions associated with the at least one interactive element. The computer system then operates the computer software at least in part using the instructions and user data determined using the user identity.