UPDATED Mar. 13, 2023, at 3:53 PM

FiveThirtyEight’s Pollster Ratings

Based on the historical accuracy and methodology of each polling organization’s polls.

B/C

Harstad Strategic Research

Polls analyzed	11
Races called correctly	77%
Most recent cycle	2014
Affiliated with AAPOR/Roper	No
Other names

What are pollster ratings?

How accurate are the polls from Harstad Strategic Research?

Polls conducted within 21 days of an election (based on the poll’s median date) are used to determine the pollster’s grade.

2014

Key

A = Adults

RV = Registered voters

V = Voters

LV = Likely voters

Dates	Sample	Race	Methodology	Poll margin	Election margin	Difference
Oct 19-23	1,004LV	Senate (CO) General election	Live Phone	Poll Udall +1.0	Actual Gardner +1.9	Difference 2.9
Oct 18-22	700LV	Senate (AK) General election	Live Phone	Poll Even	Actual Sullivan +2.1	Difference 2.1

2012

Dates	Sample	Race	Methodology	Poll margin	Election margin	Difference
Oct 21-24	600LV	Senate (PA) General election	Live Phone	Poll Casey +12.0	Actual Casey +9.1	Difference 2.9
Oct 15-17	603LV	Senate (MO) General election	Live Phone	Poll McCaskill +12.0	Actual McCaskill +15.7	Difference 3.7

2008

Dates	Sample	Race	Methodology	Poll margin	Election margin	Difference
Oct 19-22	503LV	Senate (ID) General election	Live Phone	Poll Risch +12.0	Actual Risch +23.5	Difference 11.5
Oct 19-22	503LV	President (ID) General election	Live Phone	Poll McCain +23.0	Actual McCain +25.4	Difference 2.4
Oct 19-22	273LV	House (ID-1) General election	Live Phone	Poll Minnick +7.0	Actual Minnick +1.2	Difference 5.8
Oct 19-22	230LV	House (ID-2) General election	Live Phone	Poll Simpson +44.0	Actual Simpson +42.0	Difference 2.0

2006

Dates	Sample	Race	Methodology	Poll margin	Election margin	Difference
Oct 24-25	662LV	Senate (MT) General election	Live Phone	Poll Tester +6.0	Actual Tester +0.9	Difference 5.1

2004

Dates	Sample	Race	Methodology	Poll margin	Election margin	Difference
Oct 17-18	515LV	Senate (CO) General election	Live Phone	Poll Salazar +6.0	Actual Salazar +4.8	Difference 1.2

2002

Dates	Sample	Race	Methodology	Poll margin	Election margin	Difference
Oct 14-15	400LV	House (CO-7) General election	Live Phone	Poll Feeley +1.0	Actual Beauprez +0.1	Difference 1.1

Show all

How this works

FiveThirtyEight’s pollster ratings are calculated by analyzing the historical accuracy of each polling organization’s polls along with its methodology. Accuracy scores are adjusted for the type of election polled, the poll’s sample size, the performance of other polls surveying the same race and other factors. We also calculate measures of statistical bias in the polls. When a pollster publishes multiple versions of the same survey (for example, versions with and without third-party candidates included), FiveThirtyEight uses an average of the different versions to calculate the pollster’s rating. However, all versions of these polls are listed here. Read more about our methodology»

Download this data as an Excel spreadsheet or get it on GitHub.

Design and development by Elena Mejía and Aaron Bycoffe. Research by Mary Radcliffe, Cooper Burton and Dhrumil Mehta. Copy editing by Andrew Mangan. Visual editing by Christopher Groskopf. Statistical model by Nate Silver.

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