2008 House · PA-11
SurveyUSA · fieldwork ended 2008-11-01 (3 days before the election) · 622 respondents · IVR
The poll said
Democrat 45% · Republican 51%
R+6.0
The certified result
Democrat 51.63% · Republican 48.37%
D+3.3
The arithmetic
- Poll margin = 45 − 51 = -6.00
- Actual margin = 51.627 − 48.373 = 3.254
- Signed miss = -6.00 − (3.254) = -9.255
- Absolute miss = |-9.255| = 9.255
The poll overstated the Republican by 9.3 points and had the wrong leader.
Where these numbers come from
Poll and result: 538 raw_polls.csv. Poll ID 64364, race ID 4366 (538 database).