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)
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
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.