Revisiting FastTap: Effects of Increasing Command Capacity of Spatial Memory Menus in Tablets

Spatially stable multi-touch menus, such as FastTap, utilize users’ spatial memory to enable quick command selection on tablets. Although these tablet interfaces may help develop spatial memory for small command sets, it is unknown if spatial memory remains beneficial as the number of commands increases. Therefore, we conducted a study (N=16) to examine spatial learning using four different sizes of FastTap Menus: Small, Medium, Large, and Extra-Large, containing 16, 30, 42, and 56 items, respectively. Results show that people do develop spatial memory in all menus; however, there is a negative correlation between command capacity and spatial memory development in tablets. Most people preferred smaller interfaces to larger ones. We contribute new insights into the development of spatial memory in touch tablets that can inform the design of future tablet interfaces based on spatial memory.