A Columbia Law Survey
May 2002

Conducted by       

Press Release

Fact Sheet

Vice Dean Michael Dorf's Columns About the Survey on

"Americans' Knowledge of the U.S. Constitution"
A Columbia Law Survey


 -Technical Information

 -CARAVAN Telephone Sampling Methodology

 -Reliability of Survey Percentages

 -Sampling Tolerances When Comparing Two Samples

 -Introduction to Detailed Tabulations

 -Significance Testing

 -Detailed Tabulations (requires Adobe Acrobat)






This report presents the findings of a telephone survey conducted among a national probability sample of 1012 adults comprising 503 men and 509 women 18 years of age and older, living in private households in the continental United States.

Interviewing for this CARAVANģ Survey was completed during the period May 16-19, 2002. All data collection efforts took place at Opinion Research Corporationís Central Telephone Facility in Tucson, Arizona and/or Tampa, Florida. The core of our telephone center is the interviewers. All Opinion Research Corporationís interviewers complete an intensive training and test period. Additionally, they attend follow-up training classes that cover advanced screening techniques, in-depth probing and the art of refusal avoidance. Interviewers are continuously supervised, monitored and reviewed in order to maintain the highest quality interviewing standards.

All CARAVAN interviews are conducted using Opinion Research Corporation's computer assisted telephone interviewing (CATI) system. The system is state-of-the-art and offers several distinct advantages such as: full-screen control which allows multi-question screens, fully-programmable help and objection screens to aid interviewing, an extremely flexible telephone number management system and powerful data checking facilities. CATI ensures that interviews are conducted in the most efficient manner and allows interviewers easy response recording. This interviewing method also allows for the most accurate form of data entry by guiding the interviewer through the programmed question flow and by providing on-screen interviewer instructions.

The most advanced probability sampling techniques are employed in the selection of households for telephone interviewing. Opinion Research Corporation utilizes an unrestricted random sampling procedure that controls the amount of serial bias found in systematic sampling to generate its random-digit-dial sample. The sample is fully replicated and stratified by region. Only one interview is conducted per household. All sample numbers selected are subject to up to four attempts to complete an interview.

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.

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