2008 President · IA
Big Ten · fieldwork ended 2008-10-21 (14 days before the election) · 586 respondents · Live Phone
The poll said
Democrat 52% · Republican 39%
D+13.0
The certified result
Democrat 53.93% · Republican 44.39%
D+9.5
The arithmetic
- Poll margin = 52 − 39 = 13.00
- Actual margin = 53.928 − 44.393 = 9.535
- Signed miss = 13.00 − (9.535) = 3.465
- Absolute miss = |3.465| = 3.465
The poll overstated the Democrat by 3.5 points and had the right leader.
Where these numbers come from
Poll and result: 538 raw_polls.csv. Poll ID 16709, race ID 716 (538 database).