The 30th Annual Phi Delta Kappa/Gallup Poll of the Public's Attitudes Toward the Public Schools |
DESIGN OF THE SAMPLE
For the 1998 survey the Gallup Organization used its standard national telephone sample, i.e., an unclustered, directory-assisted, random-digit telephone sample, based on a proportionate stratified sampling design.
The random-digit aspect of the sample was used to avoid "listing" bias. Numerous studies have shown that households with unlisted telephone numbers are different in important ways from listed households. "Unlistedness" is due to household mobility or to customer requests to prevent publication of the telephone number.
To avoid this source of bias, a random-digit procedure designed to provide representation of both listed and unlisted (including not-yet-listed) numbers was used.
Telephone numbers for the continental United States were stratified into four regions of the country and, within each region, further stratified into three size-of-community strata.
Only working banks of telephone numbers were selected. Eliminating non-working banks from the sample increased the likelihood that any sample telephone number would be associated with a residence.
The sample of telephone numbers produced by the described method is representative of all telephone households within the continental United States.
Within each contacted household, an interview was sought with the youngest man 18 years of age or older who was at home. If no man was home, an interview was sought with the oldest woman at home. This method of respondent selection within households produced an age distribution by sex that closely approximates the age distribution by sex of the total population.
Up to three calls were made to each selected telephone number to complete an interview. The time of day and the day of the week for callbacks were varied so as to maximize the chances of finding a respondent at home. All interviews were conducted on weekends or weekday evenings in order to contact potential respondents among the working population.
The final sample was weighted so that the distribution of the sample matched current estimates derived from the U.S. Census Bureau's Current Population Survey (CPS) for the adult population living in telephone households in the continental U.S.
COMPOSITION OF THE SAMPLE
| Adults | % |
| No children in school | 67 |
| Public school parents | 29 |
| Nonpublic school parents | 4 |
| Gender | % |
| Men | 46 |
| Women | 54 |
| Race | % |
| White | 82 |
| Nonwhite | 15 |
| Black | 11 |
| Undesignated | 3 |
| Age | % |
| 18-29 years | 22 |
| 30-49 years | 43 |
| 50 and over | 34 |
| Undesignated | 1 |
| Education | % |
| Total college | 55 |
| College graduate | 22 |
| College incomplete | 33 |
| Total high school | 44 |
| High school graduate | 28 |
| High school incomplete | 16 |
| Undesignated | 1 |
| Income | % |
| $50,000 and over | 29 |
| $40,000 and over | 40 |
| $30,000 - $39,999 | 15 |
| $20,000 - $29,999 | 15 |
| Under $20,000 | 16 |
| Undesignated | 14 |
| Region | % |
| East | 23 |
| Midwest | 24 |
| South | 32 |
| West | 21 |
| Community Size | % |
| Urban | 30 |
| Suburban | 44 |
| Rural | 26 |
TOPICS:
Introduction to the Poll
Public Versus Nonpublic Schools
Grading the Schools
Effectiveness of Public Schools
Improving the Nation's Inner-City Schools
Politics and the Public Schools
Problems Facing the Public Schools
School Operation/Curriculum
Impact of Unions
The Public's Knowledge of Local Schools
Confidence in Institutions
Closing Comments
How to Order the Poll
Research Procedure
Sampling Tolerances
Design and Composition of the Sample
Conducting Your Own Poll
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