Research Article
PaperCAD: A System for Interrogating CAD Drawings Using Small Mobile Computing Devices Combined with Interactive Paper
Table 2
Interpretation of extension lines.
| Event | Correct | Incorrect |
| Correctly interpreted | 375 | | Ink capture failure (H) | | 2 | Drawn in wrong direction, not parallel/perpendicular to anything (U) | | 3 | Drawn in wrong location (U) | | 9 | Drawn incorrectly, over-stroked (U) | | 2 | Drawn incorrectly, tapped first (U) | | 3 | Drawn on the perimeter of a circle (U) | | 1 | Drawn too far from the drawing (U) | | 5 | No pause before drawing another (U) | | 5 | Not recognized (S) | | 29 | Angle misinterpreted (S) | | 1 | Location misinterpreted (S) | | 8 | Misinterpreted as a single arrow (S) | | 3 | Misinterpreted as a tap (S) | | 4 | Total | 375 | 75 |
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H: hardware error; U: user error; S: system error.
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