2004 President · IA
Mason-Dixon Polling & Strategy · fieldwork ended 2004-10-28 (5 days before the election) · 625 respondents · Live Phone
The poll said
Democrat 44% · Republican 49%
R+5.0
The certified result
Democrat 49.23% · Republican 49.90%
R+0.7
The arithmetic
- Poll margin = 44 − 49 = -5.00
- Actual margin = 49.233 − 49.901 = -0.668
- Signed miss = -5.00 − (-0.668) = -4.332
- Absolute miss = |-4.332| = 4.332
The poll overstated the Republican by 4.3 points and had the right leader.
Where these numbers come from
Poll and result: 538 raw_polls.csv. Poll ID 4411, race ID 767 (538 database).