2012 Senate · ND
Mason-Dixon Polling & Strategy · fieldwork ended 2012-10-27 (10 days before the election) · 625 respondents · Live Phone
The poll said
Democrat 45% · Republican 47%
R+2.0
The certified result
Democrat 50.24% · Republican 49.32%
D+0.9
The arithmetic
- Poll margin = 45 − 47 = -2.00
- Actual margin = 50.238 − 49.324 = 0.914
- Signed miss = -2.00 − (0.914) = -2.914
- Absolute miss = |-2.914| = 2.914
The poll overstated the Republican by 2.9 points and had the wrong leader.
Where these numbers come from
Poll and result: 538 raw_polls.csv. Poll ID 30465, race ID 1493 (538 database).