This paper introduces a tangible programming environment that uses paper cards as command objects. We have implemented a prototype system called “Sheets”. The users can experience a tangible environment without the necessity of specialized devices using Sheets. This system is capable of drawing and moving shapes, and creates loops and branch executions. This system includes paper cards, a webcam, and software. The paper cards are printed descriptions and markers. The markers are captured by the webcam and are recognized by the software. The users can line up the command cards in a specific order to create a program, and the resulting drawing and movements of the graphic are then displayed on the screen. In addition, it is also capable of sensing real-world events such as touch inputs on these command cards, and it is possible to edit the program by writing on the paper cards. For example, the number of loop executions and the values of any variables can be altered. The program can also implement draw commands for custom sketches designed by the users. Sheets can assist in programming using functionalities like conversion to source codes and highlighting. We have performed simple evaluation experiments using this system and collected the opinions of the users.
ASJC Scopus subject areas