2008 Pollster Report Card
The table below is an assessment of pollster performance in the 2008 Presidential election. The pollsters were graded on both the accuracy of their final poll (popular vote) and the consistency of their polling during the month of October.
The overall score is a weighted average of their Accuracy and Consistency numbers. The weighting is 75% accuracy and 25% consistency. Formula details are at the bottom of this page.
| Overall | |||||
| Poll | Score | Grade | Accuracy | Consistency | |
| Rasmussen Reports | 91% | A- | 92% | 86% | |
| Ipsos/McClatchy | 89% | B+ | 92% | 79% | |
| CNN/Opinion Research | 88% | B+ | 92% | 77% | |
| Fox News | 84% | B | 92% | 61% | |
| Pew | 83% | B- | 92% | 56% | |
| GWU/Battleground | 79% | C+ | 92% | 41% | |
| Diageo/Hotline | 77% | C+ | 77% | 79% | |
| NBC News / Wall St. Journal | 76% | C | 77% | 75% | |
| Gallup Traditional | 73% | C- | 77% | 63% | |
| Marist | 67% | D+ | 62% | 82% | |
| ABC News / Wash Post | 67% | D+ | 62% | 82% | |
| IBD/TIPP | 66% | D | 77% | 34% | |
| Gallup Expanded | 66% | D | 62% | 78% | |
| CBS News / NYT | 60% | D- | 62% | 56% | |
| Reuters/C-SPAN/Zogby | 35% | F | 31% | 48% |
Data
The data for this chart come from the Real Clear Politics summary on 12 November 2008. Here is a local mirror of that data, with the final polls summarized at the top. Here is a quick summary of the final spread predicted by the pollsters, ranked from most accurate to least:
The data for this chart come from the Real Clear Politics summary on 12 November 2008. Here is a local mirror of that data, with the final polls summarized at the top. Here is a quick summary of the final spread predicted by the pollsters, ranked from most accurate to least:
| Poll | Obama | McCain | Spread (actual=6.5) | Off by | ||
| Rasmussen Reports | 52 | 46 | 6 | 0.5 | ||
| Pew | 52 | 46 | 6 | 0.5 | ||
| GWU/Battleground | 50 | 44 | 6 | 0.5 | ||
| Ipsos/McClatchy | 53 | 46 | 7 | 0.5 | ||
| CNN/Opinion Research | 53 | 46 | 7 | 0.5 | ||
| Fox News | 50 | 43 | 7 | 0.5 | ||
| Diageo/Hotline | 50 | 45 | 5 | 1.5 | ||
| NBC News / Wall St. Journal | 51 | 43 | 8 | 1.5 | ||
| Gallup Traditional | 51 | 43 | 8 | 1.5 | ||
| IBD/TIPP | 52 | 44 | 8 | 1.5 | ||
| Marist | 52 | 43 | 9 | 2.5 | ||
| ABC News / Wash Post | 53 | 44 | 9 | 2.5 | ||
| Gallup Expanded | 52 | 43 | 9 | 2.5 | ||
| CBS News / NYT | 51 | 42 | 9 | 2.5 | ||
| Reuters/C-SPAN/Zogby | 54 | 43 | 11 | 4.5 |
Formulas
Every final poll showed Obama with a lead, so assessing their accuracy is just a matter of comparing their forecasted spread with the actual spread of the election which was Obama +6.5.
Every final poll showed Obama with a lead, so assessing their accuracy is just a matter of comparing their forecasted spread with the actual spread of the election which was Obama +6.5.
Final poll accuracy score = 100 - ( |(POLL SPREAD - 6.5)| / 6.5 )
All the pollsters graded had more than one poll during the month of October. If a poll reported a wide spread and then suddenly narrowed down right before the election, this formula produces a lower score. Likewise a pollster gets a lower score if they predicted a very tight race until the end and then widened up.
October Consistency = 100 - ( POLL STDEV / POLL AVERAGE )
