especially with the presence of a figure, require users to register click-based
password with pinpoint accuracy.
When using a touch screen device, the user’s finger, hand and arm can obscure
part of the screen. Also, the human finger as a pointing device has very low
“resolution”. These limitations have been observed and tackled before, mostly
notably by Sears, Shneiderman and colleagues (Sears, 1991, Sears et al., 1992).
Their basic technique, called Take-Off, provides a cursor above the user’s finger tip
with a fixed offset when touching the screen. The user drags the cursor to a desired
target and lifts ...