Question

Match the following errors (Column 1) in spatial data digitization with their descriptions (Column 2).
 

Column 1	Column 2
(P) Mis-located entities	2) Points, lines or boundary segments digitized in wrong place
(Q) Missing labels	4) Undefined polygons
(R) Artefacts of digitization	3) Undershoots, overshoots, wrongly placed nodes, loops or spikes
(S) Duplicate labels	5) Two or more identification labels for same polygon
(T) Duplicate entities	1) Points, lines or boundary segments digitized twice

• A. P-2, Q-4, R-3, S-5, T-1
• B. P-1, Q-2, R-3, S-5, T-4
• C. P-2, Q-1, R-4, S-3, T-5
• D. P-2, Q-4, R-3, S-1, T-5

Hint:

Digitizing QA cheat sheet: mis-located = wrong place; artefacts = geometry errors (overshoot/undershoot/spikes); missing labels = undefined polygons; duplicate labels = multiple IDs on one polygon; duplicate entities = same feature traced twice.

Answer 1

The Correct Option is A

P $⇒$ 2 (Mis-located entities).
“Digitized in the wrong place” directly describes mis-location.
Q $⇒$ 4 (Missing labels).
Polygons without IDs (labels) are undefined polygons.
R $⇒$ 3 (Artefacts of digitization).
Typical digitizing artefacts include undershoots, overshoots, bad nodes, loops, spikes.
S $⇒$ 5 (Duplicate labels).
Two or more IDs placed on the same polygon.
T $⇒$ 1 (Duplicate entities).
The same feature captured twice (points/lines/boundaries).