This chapter discusses research methods and findings in the context of the broader spectrum of processes involved in disasters. The discussion of the state of the art focuses on three aspects of disaster research: methodology, vulnerability, and estimates of morbidity and mortality. The study of disasters can occur in many different physical and temporal contexts. Disaster research, as with most other types of research, utilizes both qualitative and quantitative data. Surveys of individuals, healthcare providers, and healthcare organizations are heavily utilized in disaster epidemiology to obtain quantitative data about the health status of a population and possible associations between disaster exposure and health outcomes. The most commonly mentioned dimensions of vulnerability in disaster research are physical, economic, political, social, and psychological. The discussion of disaster morbidity and mortality describes how these estimates are derived, as well as the many factors that can influence their accuracy and introduce variability across studies.