2018 House · IA-4
Emerson College · fieldwork ended 2018-10-31 (6 days before the election) · 356 respondents · IVR/Online Panel
The poll said
Democrat 41.7% · Republican 51%
R+9.3
The certified result
Democrat 47.04% · Republican 50.37%
R+3.3
The arithmetic
- Poll margin = 41.7 − 51 = -9.30
- Actual margin = 47.037 − 50.368 = -3.331
- Signed miss = -9.30 − (-3.331) = -5.968
- Absolute miss = |-5.968| = 5.968
The poll overstated the Republican by 6.0 points and had the right leader.
Where these numbers come from
Poll and result: 538 raw_polls.csv. Poll ID 56672, race ID 300 (538 database).