Classical methods for detecting outliers deal with continuous variables. These methods are not readily applicable to categorical data, such as incorrect/correct scores (0/1) and ordered rating scale scores (e.g., 0,..., 4) typical of multi-item tests and questionnaires. This study proposes two definitions of outlier scores suited for categorical…

The purpose of this paper is to provide a detailed description of the Monitoring the Future research design, including sampling, data collection procedures, measurement content, and questionnaire format. Monitoring the Future is designed to assess the changing lifestyles, values, and preferences of American youth on a continuing basis. Since the…

This study is intended to assess the changing lifestyles, values, and preferences of American youth on a continuing basis. Each year since 1975, about 17,000 seniors have participated in the survey, which is conducted in about 130 high schools nationwide. In addition, subsamples of seniors from previously participating classes receive follow-up…

This occasional paper is intended to disseminate information from the project, Monitoring the Future. Each year since 1975, about 17,000 seniors have participated in the survey, which is conducted in some 130 high schools nationwide. In addition, subsamples of seniors from previously participating classes receive follow-up questionnaires by mail…

This paper is a companion to the book, "Smoking, Drinking, and Drug Use in Young Adulthood: The Impacts of New Freedoms and New Responsibilities," by Bachman, Wadsworth, O'Malley, Johnston, and Schulenberg (1997). The book attempts to disentangle the effects of post-high school roles on drug use by conducting a variety of analyses on…

This book focuses on transitions into young adulthood by examining key roles and experiences of young adults and how they relate to changes in drug use. The findings are based on the nationwide Monitoring the Future project, and represent the majority of individuals who entered young adulthood in the United States during the years 1976 through…

This paper presents information from the ongoing research program, Monitoring the Future. The program is designed to: (1) monitor drug use and potential explanatory factors among American secondary school students, and other young adults; (2) distinguish which of three different kinds of change--maturational, historical, and/or cohort are…