Roanoke College Institute for Policy and Opinion Research
Graded against the actual result across 18 races (from 29 polls, through 2021).
Head-to-head vs VotePredictor Elections
The fair, apples-to-apples test: on the 15 races Roanoke College Institute for Policy and Opinion Research actually polled, how its final poll's margin compared to what VotePredictor Elections predicted for those same races.
| Model | Avg miss (pts) | Called right |
|---|---|---|
| Roanoke College Institute for Policy and Opinion Research | 5.03 | 67% |
| VotePredictor Elections | 3.58 | 100% |
VotePredictor Elections aggregates all the pollsters, so it's expected to beat any single one on margin — that's the value of averaging. The honest comparison among forecasters is on the combined board.
Every race (18)
Each race Roanoke College Institute for Policy and Opinion Research polled, scored on its final poll — the call right before the vote — against the actual Dem−Rep result. Click a race for its full detail.
| Race | Their call | Result | Miss | Call |
|---|---|---|---|---|
| 2021 VA Governor | D+1.0 | R+1.9 | 2.9 | ✗ |
| 2020 VA President | D+11.0 | D+10.1 | 0.9 | ✓ |
| 2020 VA Senate | D+16.0 | D+12.1 | 3.9 | ✓ |
| 2017 VA Governor | EVEN | D+8.9 | 8.9 | ✗ |
| 2016 VA President | D+7.0 | D+5.3 | 1.7 | ✓ |
| 2014 VA Senate | D+10.0 | D+0.8 | 9.2 | ✓ |
| 2013 VA Governor | D+15.0 | D+2.5 | 12.5 | ✓ |
| 2012 VA President | R+5.0 | D+3.9 | 8.9 | ✗ |
| 2012 VA Senate | R+5.0 | D+5.9 | 10.9 | ✗ |
| 2010 VA-5 House | R+6.0 | R+3.8 | 2.2 | ✓ |
| 2009 VA Governor | R+16.0 | R+17.4 | 1.4 | ✓ |
| 2008 VA President | D+9.0 | D+6.3 | 2.7 | ✓ |
| 2008 VA Senate | D+35.0 | D+31.3 | 3.7 | ✓ |
| 2006 VA Senate | R+3.0 | D+0.4 | 3.4 | ✗ |
| 2005 VA Governor | D+8.0 | D+5.7 | 2.3 | ✓ |
| 2001 VA Governor | D+9.0 | D+5.1 | 3.9 | ✓ |
| 2000 VA President | R+2.0 | R+8.0 | 6.0 | ✓ |
| 2000 VA Senate | R+6.0 | R+4.6 | 1.4 | ✓ |
Accuracy by time to election
Lower is better. Time to election runs right (election week) to left (~2 months out).
By the numbers
| Time to election | Polls | Avg miss | vs field | Called right |
|---|---|---|---|---|
| 1–3 wk | 16 | 5.61 | +0.54 | 69% |
| 3–6 wk | 7 | 4.20 | -1.54 | 86% |
| 6–9 wk | 6 | 5.63 | -0.52 | 100% |
vs field is this pollster's average miss minus all pollsters' at the same lead time — green beats the field, redtrails it. Our historical polls reach ~2 months out; earlier polling isn't in the record.
Track record by cycle — getting better?
| Year | Polls | Avg miss | Lean (house effect) |
|---|---|---|---|
| 2012 | 4 | 7.0 | R+2.9 |
| 2013 | 3 | 5.8 | D+4.8 |
| 2016 | 4 | 4.9 | D+4.9 |
| 2017 | 3 | 5.6 | R+5.6 |
Do we credit a pollster for fixing its bias? Each cycle, the model re-estimates every pollster's lean from all its earlier polls (walk-forward) and subtracts it before using the poll. We tested weighting recent cycles more — it doesn't help: a pollster's lean in one cycle barely predicts the next (correlation 0.28), so the swings above are mostly noise, and averaging over more history beats chasing the latest cycle. The all-time estimate we use came out within ~0.5% of the best option.