The Sampling Bias in Random Digit Dialing

by A. Dianne Schmidley' Bell Atlantic Corporation All research is based on information from data collection efforts, whether the data result from the use of qualitative approaches, such as, content analysis, focus group sessions, or in-depth interviewing by psychologists, social workers or ethnographers, or from methods which produce data more amenable to quantitative analyses, such as, sample surveys and censuses (technically, a census is a 100% sample stirvey). A study-, conducted by Derek Phillips in the early 1970s, concerning the preference of sociologists for either qtiantitative or qualitative data collection approaches, revealed that more than 90 percent of the research conducted by those social scientists resulted from the analysis of data collected through the administration of interview schedules and/or questionnaires developed for use in a survey setting.