The provision of home-based services for individuals or families in the United States dates from colonial times and remains prevalent in education, social service, and health agencies. These services are offered by a professional or paraprofessional who enters the home of a client to provide information, health care, psychological counseling, or other support services over a sustained period of time Wasik, Bryant, & Lyons, 1990). As long ago as the 1860s, issues were raised about the qualifications, training, and supervision of those who would provide home visiting services. Florence Nightingale, one of the pioneers of home visiting, devoted considerable attention to the importance of training (Monteiro, 1985). The hiring and training of home visitors was also addressed in the classic book, Friendly Visiting Among the Poor, by Richmond (1899). From the late 1800s into the early 1900s, home visiting services were developed to address conditions associated with urbanization and immigration, including poverty, contagious diseases, high infant mortality, and poor school attendance. These efforts, part of the general social reform movement of the time, received less attention in the 1920s (Levine & Levine, 1970). By mid-century, several events converged to generate renewed attention to home visiting as a service delivery procedure (Wasik, 1993). These events included a recognition that the home was often a more desirable setting for the care of children with disabilities than was an institution, that parents of children with special needs have an important role in their children's social and cognitive development, and that at times parents need help in caring for their children with special needs. Since the 1970s, a rapid expansion has occurred in the provision of home visiting services. Both Hawaii and Missouri have statewide home visiting programs (Gomby, Larson, Lewitt, & Behrman, 1993). The U.S. General Accounting Office (1990), based on its analysis of home visiting programs, has recommended home visiting as a service delivery program, especially for infants and mothers. The National Commission to Prevent Infant Mortality (1989) is promoting home visiting through its Resource Mothers program, which employs mothers as lay home visitors. The U.S. Advisory Board on Child Abuse and Neglect 1991) has strongly recommended a universal voluntary neonatal home visiting system for the prevention of child abuse and neglect. In 1992 and 1993, the Bureau of Maternal and Child Health funded a total of 41 community integrated service system projects to help reduce infant mortality and improve maternal health. In 1992, over 80% of the funded programs included home visiting services. In 1933, legislation was passed authorizing the expenditure of $1 billion over 5 years for family preservation and family support (Gomby et al., 1993). A number of home visiting programs has been described in the literature, including those designed to prevent child abuse and neglect (see Dubowitz, 1990, and Fink & McCloskey, 1990, for reviews), to enhance children's cognitive development (Wasik, Ramey, Bryant, & Sparling, 1990), to improve prenatal and postnatal outcomes (Olds, Henderson, & Kitzman, 1994), or to reduce out-of-home placements for adolescents (Henggeler, Melton, & Smith, 192; Kinney, Haapala, & Booth, 1991). This wide diversity in populations served and in program goals among home visiting programs has led to debate about the appropriate characteristics of home visitors. Discussion has focused on issues of employment criteria, especially the employment of professional home visitors versus paraprofessional home visitors, preemployment training and experience, professional skills essential for home visitors, and the importance of training and supervision following hiring (Fenichel, 1992; Halpern, 1992; Larner & Halpern, 1987; Wasik, Bryant, & Lyons, 1990). Possibly the most intense debate regarding home visiting focuses on whether to employ professional or paraprofessional home visitors. …