2008 House · MI-9
Grove Insight · fieldwork ended 2008-10-21 (14 days before the election) · 400 respondents · Live Phone · partisan sponsor (DEM)
The poll said
Democrat 46% · Republican 36%
D+10.0
The certified result
Democrat 52.08% · Republican 42.63%
D+9.5
The arithmetic
- Poll margin = 46 − 36 = 10.00
- Actual margin = 52.082 − 42.628 = 9.454
- Signed miss = 10.00 − (9.454) = 0.546
- Absolute miss = |0.546| = 0.546
The poll overstated the Democrat by 0.5 points and had the right leader.
Where these numbers come from
Poll and result: 538 raw_polls.csv. Poll ID 64087, race ID 4232 (538 database).