2012 House · IL-8
Impact Research · fieldwork ended 2012-10-17 (20 days before the election) · 400 respondents · Live Phone · partisan sponsor (DEM)
The poll said
Democrat 54% · Republican 39%
D+15.0
The certified result
Democrat 54.74% · Republican 45.26%
D+9.5
The arithmetic
- Poll margin = 54 − 39 = 15.00
- Actual margin = 54.742 − 45.258 = 9.484
- Signed miss = 15.00 − (9.484) = 5.516
- Absolute miss = |5.516| = 5.516
The poll overstated the Democrat by 5.5 points and had the right leader.
Where these numbers come from
Poll and result: 538 raw_polls.csv. Poll ID 51559, race ID 5035 (538 database).