Assessing and Interpreting Public Opinion

Important Terms

Population Sample Bias/Error

Sampling Error Coverage Error Non-Response Response Bias Measurement Error

Important Terms

Population Sample Bias/Error

Sampling Error Coverage Error Non-Response Response Bias Measurement Error

Important Terms

Population Sample Error/Bias

Sampling Error Coverage Error Non-Response Response Bias Measurement Error

Public Opinion on Abortion

Question # 1 Which of these statements comes

closest to your opinion? Abortion is the same thing as murdering a child, or abortion is not murder because a fetus isn’t really a person. Murder 55% Not murder 35 Don’t know, not ascertained 10

Public Opinion on Abortion

Question # 2 Do you agree or disagree with the

following statement? Abortion sometimes is the best course in a bad situation. Agree 66% Disagree 26 Don’t know, not ascertained 8

Public Opinion on Abortion

Question # 3: What do you think about abortion? Should it

be legal as it is now, legal only in such cases as saving the life of the mother, rape, or incest, or should it not be permitted at all? Legal as is now 40% Legal only to save mother, rape, incest

40 Not permitted 16 Don’t know, no answer 4

Literary Digest Poll for 1936

1928 & 1932 polls had been successful

1936 contest seemed competitive

Literary Digest Poll for 1936

44 Million potential voters 10 Million ballots distributed 2.4 Million returned

Estimated election results: FDR 43% Alf Landon 57%

Literary Digest Poll for 1936

Real election results: FDR 62% Landon 38%

1936 Election Outcome: Correctly Predicted by Gallup

Afterward Gallup dominated polling

Gallup Poll of 1948

quota sampling Prediction: Truman 44.5% (lose) Real election results: Truman 49.9

(win)

Measurement Error: Question Wording

Holocaust Survey MishapRoper Organization (1992): Does it seem possible or does it seem impossible to you that the Nazi extermination of the Jews never happened? (65%) Impossible it never happened (12%) Don't know (22%) Possible it never happened

Confusing question

Question Wording

(March 1994) – Gallup Organization

Does it seem possible to you that the Nazi extermination of the Jews never happened or do you feel certain that it happened? (91%) Certain it happened (8%) Don't know (1%) Possible it never happened

Question Wording

• Leading questions• Double-barreled questions• Push polls

Measurement Error: Respondent Effects

• Memory• Ignorance• Social desirability

Measurement Error:Respondent Effects

Measurement Error:Question Wording (Framing)

Would you favor or oppose federal assistance to industries in economic trouble?

 Would you favor or oppose a federal "bailout" of industries in economic trouble?

Measurement Error:Question Wording (Framing)

Would you favor or oppose cutting federal aid to the needy in order to cut federal spending?

 Would you favor or oppose cutting welfare programs in order to cut federal spending?

Opinion is Ill-Informed

Governmental Structure•39% did not know Republicans took over the U.S. House in 1994•Only 26% knew a U.S. Senator served for 6 years•Only half knew the Republicans were more conservative than the Democrats•Only half knew SCOTUS has last say on whether a law is constitutional•Only 6% could name Rehnquist as the Chief Justice•Only 34% could name Dole as the Senate Majority Leader•Only 53% could name Gingrich as the House Speaker•Only 60% could name Gore as the Vice President

Social Conditions•59% thought elderly poverty had increased over 20 years; it had dropped sharply•91% thought violent crime had increased from 1976-1996; it had dropped significantly•69% thought the budget deficit had increased from 1993-1996 despite negotiated decreases

Government Policies•58% thought we spent more on Foreign Aid than Medicare•32% thought government policy had made this situation worse, despite large handouts

Use of Polls

Rachel Maddow (and others): 72% of Foxnews viewers oppose the Civil Rights Act

Is this an accurate depiction?

Actual Question

Actual Question

Civil Rights Act (1964)

Title I: Equal Application of Voter Registration Standards

Title II: No discrimination in “public accommodations engaged in interstate commerce”

Title III: Sub-National Governments cannot ban access to public facilities based on race, gender, religion, ethnicity

Title IV: Attorney General can sue to enforce desegregation

Title V: Expanded powers of Civil Rights Commission Title VI: No discrimination by government agencies

that receive federal funding

Use of Polls

Do you support the Civil Rights Act of 1964? Yes: 28% No: 72%

Would the conclusion “72% of Foxnews viewers oppose Civil Rights Act” be accurate?

Consider this…

A national survey: 52% favor Obama 48% favor McCain

+/- 3% margin of error

The Leader is…

Obama could be supported by as low as 49%

McCain could be favored by as high as 51%

Does it makes sense to use a national opinion poll to predict winners?