Vice Dean Michael Dorf's Columns About the Survey on FindLaw.com
"Americans' Knowledge of the U.S.
A Columbia Law Survey
-CARAVAN Telephone Sampling Methodology
-Reliability of Survey Percentages
-Sampling Tolerances When Comparing Two Samples
-Introduction to Detailed Tabulations
-Detailed Tabulations (requires Adobe Acrobat)
Completed interviews are weighted by four variables: age, sex, geographic
region, and race, to ensure reliable and accurate representation of the total
population, 18 years of age and older. The raw data are weighted by a custom
designed program which automatically develops a weighting factor for each
respondent. Each respondent is assigned a single weight derived from the
relationship between the actual proportion of the population with its specific
combination of age, sex, geographic characteristics and race and the proportion
in our CARAVAN sample that week. Tabular results show both weighted and
The use of replicable sampling, standardized interviewing procedures and
representative weighting provides that all CARAVAN studies are parallel to one
another. Thus, CARAVAN usage is appropriate both for point-in-time analysis as
well as tracking and trend comparisons.
Included in the Technical Information which follows are tables of sampling
tolerances of survey results, and a copy of the question series as it appeared
in the survey questionnaire.
As required by the Code of Standards of the Council of American Survey Research
Organizations, we will maintain the anonymity of our respondents. No information
will be released that in any way will reveal the identity of a respondent. Our
authorization is required for any publication of the research findings or their
Opinion Research Corporation's CARAVAN is a shared-cost data collection vehicle.
Opinion Research Corporation has exercised its best efforts in the preparation
of this information. In any event, Opinion Research Corporation assumes no
responsibility for any use which is made of this information or any decisions
based upon it.