2012 House · MI-3
Glengariff Group · fieldwork ended 2012-10-17 (20 days before the election) · 400 respondents · Live Phone
The poll said
Democrat 35% · Republican 34%
D+1.0
The certified result
Democrat 44.17% · Republican 52.62%
R+8.4
The arithmetic
- Poll margin = 35 − 34 = 1.00
- Actual margin = 44.167 − 52.615 = -8.448
- Signed miss = 1.00 − (-8.448) = 9.449
- Absolute miss = |9.449| = 9.449
The poll overstated the Democrat by 9.4 points and had the wrong leader.
Where these numbers come from
Poll and result: 538 raw_polls.csv. Poll ID 51361, race ID 5097 (538 database).