Skip to content

2018 House · SD-1

Change Research · fieldwork ended 2018-11-03 (3 days before the election) · 851 respondents · Text-to-Web/Online Ad

The poll said

Democrat 41% · Republican 51%

R+10.0

The certified result

Democrat 36.02% · Republican 60.33%

R+24.3

The arithmetic

  1. Poll margin = 41 − 51 = -10.00
  2. Actual margin = 36.025 − 60.332 = -24.307
  3. Signed miss = -10.00 − (-24.307) = 14.307
  4. Absolute miss = |14.307| = 14.307

The poll overstated the Democrat by 14.3 points and had the right leader.

Where these numbers come from

Poll and result: 538 raw_polls.csv. Poll ID 56760, race ID 518 (538 database).