PaperCAD: A System for Interrogating CAD Drawings Using Small Mobile Computing Devices Combined with Interactive Paper

Table 5

Interpretation of curved arrows.

Event	Correct	Incorrect
Correctly interpreted	68
Did not complete drawing the arrow before timeout (U)		3
Forgot to pause and attempted to draw another arrow (U)		1
Missing one arrowhead (U)		1
Misinterpreted as a single arrow (S)		6
Misinterpreted as missing a datum (S)		1
Total	68	12

U: user error; S: system error.