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RTI Stories

Advances in Survey Technology: CATI, ACASI, and SUDAAN

RTI introduces new tools to increase the reliability of data collection

Always in the forefront of survey research, in 1995 RTI introduced a new methodology in household survey interviewing techniques. That year, for the National Survey of Family Growth (NSFG), institute researchers deployed both computer-assisted telephone interviewing (CATI) and a new technology called audio computer-assisted self-interviewing (ACASI) tailored to the sensitive nature of deeply personal questions.

The NSFG survey, funded by the National Center for Health Statistics (a division of the Centers for Disease Control), sought to shed light on the quality of health services and health education provided to pregnant teenagers, concerns among women about cancer of the reproductive organs, and the needs and concerns of mothers working outside the home who required help with child care.

For NSFG, RTI researchers interviewed 10,400 women of childbearing age across the country, many of the questions involving respondents' past and current drug use and sexual habits. ACASI, developed by Judith Lessler, James O’Reilly, and Charles Turner, involves a computer playing recorded questions, along with answer choices, to a respondent wearing headphones in a private setting, who answers the questions using the computer’s keyboard. The computer records the response and, based on the answer, selects and plays the next appropriate question.

Deployed for NSFG, ACASI provided a much-needed level of comfort for respondents when answering sensitive questions, such as whether they had ever had an abortion. Data on abortion had been underreported in the United States by as much as 50 percent, according to fertility surveys at the time, and ACASI helped produce more accurate and detailed survey data for study by health care policymakers.

ACASI subsequently became the preferred methodology in survey and policy research involving highly sensitive topics, from health care and eating habits to substance abuse and sexual practices. In 1997, RTI unveiled the latest iteration of the technology–touch-screen self-administered interviewing. Rather than listening to questions over a headset, the respondent simply reads them on a computer and touches the appropriate response on the screen.

RTI's technological leadership in survey methodology was not limited to interviewing. In 1984, the Institute introduced SUDAAN, the first statistical software designed to analyze correlated data collected from complex surveys. RTI's biometrics chief scientist, Babubhai V. Shah, led the team that developed SUDAAN, which quickly became the standard tool in the profession. Shah named the software SUDAAN for two reasons–first, it's a shorthand acronym for "survey data analysis" and second, because the word "sudaan" in Sanskrit, means “beautiful gift.”