Sorry if this has already been posted, but I wanted to take a final look at how the polls did predicting the Warren-Brown race. Poll data courtesy of RealClearPolitics.com:
Actual election result: Warren +7.4
Suffolk/7News: Warren +7. Despite their national embarrassment of pulling out of 3 states they claimed were non-competitive for Romney, when those states turned out to be, um, pretty competitive after all, Suffolk nailed this race. Poll done 10/25 – 10/28.
Public Policy Polling: Warren +6. Also did well predicting the final result. This one used the most recent data of the group at 11/1-11/2 and the largest sample size, 1,089 likely voters.
WBUR/MassINC: Warren +6. Predicted the result despite less recent data, taken 10/21-10/22.
Rasmussen: Warren +5. Despite their often Republican lean, their final poll on 10/25 was reasonably close. However, earlier polls skewed more Republican; for example, their late September poll showed a tie while many others had Warren with a comfortable lead.
Western NE University: Warren +4. Correct result, slightly underestimated the margin. Data from 10/26-11/1.
Boston Globe: Tie. Taken 10/24-10/28. Helped feed the media meme of a horserace — and encouraged volunteers to GOTV; but not very helpful in predicting the result.
UMass/Boston Herald: Brown +1. Worst of the lot, and using recent data, no less: 10/31-11/3. This poll skewed heavily Brown in September also, showing Brown up 4 when every other poll except Rasmussen’s tie showed Warren with a lead. I’m guessing there was a problem with their overall voter sample weighting, their “7-item turnout scale” likely voter methodology, or both.