Public Opinion
& Polling

Public Opinion
“...those opinions held by private
persons which government finds
it prudent to heed.”--V.O. Key, Jr.

Does Public Opinion Matter?

“The republican principle demands
that the deliberative sense of the
community should guide the conduct
of those to whom they entrust the
management of their affairs; but it
does not require an unqualified
complaisance to every sudden breeze
of passion, or to every transient
impulse which the people may receive
from the arts of men, who flatter
their prejudices to betray their
interest...” --Alexander Hamilton, Federalist 71

Public Opinion
The collection of independent
politically relevant opinions that
ordinary citizens express openly
through words or actions.

How do we
measure
public
opinion?

Scientific vs. Unscientific Polling

The
Theory
of
Probability

Probability Sample
sample design in which each
individual in the population has a
known probability of being
randomly selected for inclusion in
a survey or poll

Sampling Error?

Sample Size Margin of Error (%)
2000 +/-2%
1000 +/-3%
600 +/-5%
400 +/-6%
200 +/-8%
100 +/- 11%

The Bell Curve
68%
95%

The Phone Book List
Problem

1990 U.S. Census

Public Opinion Poll
a relatively few individuals (the
sample) are interviewed in order
to estimate the opinions of a
whole population.

Survey
Systematic interviews by trained,
professional interviewers, who ask
a standardized set of questions of
a rather small number of
randomly chosen citizens.

Unscientific Polling

Straw Polls
Unscientific surveys of
popular views.
(NO RANDOM SAMPLE)

Problems with Polling

1936 Presidential Election

The
Importance
of Random
Sampling

The
Gallup
Poll

What About Timing?

1948 Presidential Election

Exit Poll
Interviews of voters are taken as
they leave the polling place.

2004 Zogby Exit Polls

5”
Today’s Date Last Name, First Name
(mm/dd/yy)
3” PLACE ANSWER HERE

5”
Question of the Day
How do you feel about Dr. Rice as
a Political Science instructor?
A. He’s supercalifragilisticexpialidocious!
3” B. He’s pretty good, but his fashion
choices leave a lot to be desired…
C. He’s not nearly as great as he thinks he
is.
D. Where did they dig this guy up?

5”
Question of the Day
How would you feel about Dr. Rice as a
Political Science instructor if you knew that
he liked to kick dogs, eat small children and
club baby seals?
3” A. He’s supercalifragilisticexpialidocious!
B. He’s pretty good, but his fashion choices
leave a lot to be desired…
C. He’s not nearly as great as he thinks he is.
D. Where did they dig this guy up?

Push polls
unscientific polls that
deliberately feed respondents
misleading information or
leading questions in an effort
to “push” them into favoring a
particular candidate or issue