While many technologies that support assistance in physical
tasks are finding widespread use, little research has been con-
ducted to evaluate their efficiency and effectiveness in these
settings. One class of collaboration technologies are handheld
mobile devices, such as smartphones and tablet computers,
which are equipped with videoconferencing capabilities that
can enhance collaboration [8]. Tablets are also becoming in-
creasingly popular for both work and casual use [9]. The larger
screen size of a tablet computer relative to the smartphone may