“…These explorations involved gathering data from a variety of sources including prior art HCI and CSCW literature describing existing digital tabletop systems, (e.g., Rekimoto and Saitoh, 1999;Streitz et al, 1999Streitz et al, , 2001; de Bruijn and RUSSELL KRUGER ET AL. Spence, 2001;Deitz and Leigh, 2001;Hancock and Booth, 2004;Shen et al, 2001Shen et al, , 2002Tandler et al, 2001;Stathis et al, 2002;Vernier et al, 2002), HCI and CSCW literature involving qualitative and quantitative studies focused on tabletop collaboration or single-user tabletop interaction, (e.g., Tang, 1991;Fitzmaurice, et al, 1999).…”