Using data from the 1991, 1995, and 1999 Adult Education Surveys of the National Household Education Surveys Program to examine participation rates in adult education over time, this report examines participation among different groups of adults (by age, sex, race/ethnicity, education level, labor force status, occupation group, and whether the adult has continuing education requirements), and for different types of adult education (adult basic education, English as a Second Language programs, credential programs, apprenticeship programs, work-related courses, and non-work-related courses). For work-related courses and non-work-related courses in 1999, a multivariate statistical analysis was used to help reveal the socio-demographic determinants of participation in these activities.