HZA evaluates specific programs, services and casework tools. Data are collected through interviews, focus groups, document reviews, site visits, surveys and from a variety of management information systems. State agency program evaluations span a wide range of areas, including substance abuse, mental health, courts and corrections, and child welfare. HZA also works with private entities to evaluate local, regional and state level projects in the areas of substance abuse prevention and treatment, co-occurring disorders, and public health topics such as health promotion and disease prevention.