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

Arizona State University Morrison Institute for Public Policy

Polls analyzed	8
Races called correctly	100%
Most recent cycle	2008
Affiliated with AAPOR/Roper	No
Other names

What are pollster ratings?

How accurate are the polls from Arizona State University Morrison Institute for Public Policy?

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

2008

Key

A = Adults

RV = Registered voters

V = Voters

LV = Likely voters

Dates	Sample	Race	Methodology	Poll margin	Election margin	Difference
Oct 23-26	1,019RV	President (AZ) General election	Live Phone	Poll McCain +2.0	Actual McCain +8.5	Difference 6.5
Jan 17-20	375LV	President (AZ) Republican primary	Live Phone	Poll McCain +23.0	Actual McCain +12.6	Difference 10.4
Jan 17-20	366LV	President (AZ) Democratic primary	Live Phone	Poll Clinton +21.0	Actual Clinton +8.0	Difference 13.0

2006

Dates	Sample	Race	Methodology	Poll margin	Election margin	Difference
Oct 19-22	1,019LV	Governor (AZ) General election	Live Phone	Poll Napolitano +43.0	Actual Napolitano +27.1	Difference 15.9
Oct 19-22	1,019LV	Senate (AZ) General election	Live Phone	Poll Kyl +6.0	Actual Kyl +9.8	Difference 3.8

2004

Dates	Sample	Race	Methodology	Poll margin	Election margin	Difference
Oct 19-21	573RV	President (AZ) General election	Live Phone	Poll Bush +5.0	Actual Bush +10.5	Difference 5.5

2002

Dates	Sample	Race	Methodology	Poll margin	Election margin	Difference
Oct 19-21	300LV	Governor (AZ) General election	Live Phone	Poll Napolitano +8.0	Actual Napolitano +1.0	Difference 7.0

2000

Dates	Sample	Race	Methodology	Poll margin	Election margin	Difference
Oct 19-22	600LV	President (AZ) General election	Live Phone	Poll Bush +10.0	Actual Bush +6.3	Difference 3.7

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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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