2010 House · IL-17
PSB Research · fieldwork ended 2010-10-13 (20 days before the election) · 417 respondents · Live Phone
The poll said
Democrat 38% · Republican 45%
R+7.0
The certified result
Democrat 42.96% · Republican 52.58%
R+9.6
The arithmetic
- Poll margin = 38 − 45 = -7.00
- Actual margin = 42.964 − 52.581 = -9.617
- Signed miss = -7.00 − (-9.617) = 2.617
- Absolute miss = |2.617| = 2.617
The poll overstated the Democrat by 2.6 points and had the right leader.
Where these numbers come from
Poll and result: 538 raw_polls.csv. Poll ID 51784, race ID 4605 (538 database).