2012 House · SD-1
Nielson Brothers Polling · fieldwork ended 2012-10-30 (7 days before the election) · 771 respondents · IVR
The poll said
Democrat 44% · Republican 50%
R+6.0
The certified result
Democrat 42.55% · Republican 57.45%
R+14.9
The arithmetic
- Poll margin = 44 − 50 = -6.00
- Actual margin = 42.550 − 57.450 = -14.900
- Signed miss = -6.00 − (-14.900) = 8.899
- Absolute miss = |8.899| = 8.899
The poll overstated the Democrat by 8.9 points and had the right leader.
Where these numbers come from
Poll and result: 538 raw_polls.csv. Poll ID 30615, race ID 5248 (538 database).