Sears, A., Shneiderman, B. (June 1989)
Three studies were conducted comparing speed of performance, error rates, and user preference ratings for three selection devices. The devices tested were a touchscreen, a touchscreen with stabilization (stabilization software filters and smooths raw da ta from hardware), and a mouse. The task was the selection of rectangular targets 1,4,16,32 pixels per side (0.4x0.6, 1.7x2.2, 6.9x9.0, 13.8x17.9 mm respectively). Touchscreen users were able to point at single pixel targets, thereby countering widespre ad expectations of poor touchscreen resolution. The results show no difference in performance between the mouse and touchscreen for targets ranging from 32 to 4 pixels per side. In addition, stabilization significantly reduced the error rates for the to uchscreen when selecting small targets. These results imply that touchscreens, when properly used, have attractive advantages in selecting targets as small as 4 pixels per size (approximately one-quarter of the size of a single character). Ideas for fut ure research are presented.