2004 President · IA
Mason-Dixon Polling & Strategy · fieldwork ended 2004-10-17 (16 days before the election) · 625 respondents · Live Phone
The poll said
Democrat 43% · Republican 49%
R+6.0
The certified result
Democrat 49.23% · Republican 49.90%
R+0.7
The arithmetic
- Poll margin = 43 − 49 = -6.00
- Actual margin = 49.233 − 49.901 = -0.668
- Signed miss = -6.00 − (-0.668) = -5.332
- Absolute miss = |-5.332| = 5.332
The poll overstated the Republican by 5.3 points and had the right leader.
Where these numbers come from
Poll and result: 538 raw_polls.csv. Poll ID 4658, race ID 767 (538 database).