The National Occupational Research Agenda (NORA) Exposure Assessment Methods (EAM) Team has proposed definitions and prioritized recommendations for research related to the field of exposure assessment. Proposed research falls into four areas: study design, monitoring methods, applied toxicology, and education and communication. The purpose of this document is to stimulate new research in these areas. Study Design: Basic to the success of any exposure assessment is the study design and its inherent sampling strategy. Standardized data collection is a high priority, along with a practical exposure assessment guide. Research to refine job exposure matrices is needed, and a national occupational exposure survey of current conditions that will then be continually updated should be established. Another priority is a National Occupational Exposure Database (NOEDB) for storing exposure data from a diversity of sources and disseminating the data for a wide variety of research efforts. Continued research on the statistical analysis of exposure data is the final priority in the study design area. Monitoring Methods: Measurement tools (methods and instruments) are fundamental to exposure assessment. There are three key needs in this category. The first priority is the development of guidelines for evaluating monitoring methods against standard performance criteria. The second priority topic is the development of dermal exposure assessment and biomonitoring methods. The third priority is the development of rapid, field-deployable methods. Applied Toxicology: Understanding the underlying toxicological relationships-such as between workplace exposure and internal dose, target-organ dose, pre?clinical effects, and clinical effectsis fundamental to exposure assessment. Four recommendations are made in this area. The first calls for more mechanistic research on chemical, physical, and biological agents. The second addresses the need for a toxicity assessment protocol. The third need is for the development and evaluation of pharmacokinetic and predictive models. The fourth is a call for more research on a general toxicology approach to assess exposures to mixtures. Education and Communication: Research scientists in exposure assessment should have knowledge of the goals and limitations of exposure assessment strategies to ensure that methods they develop and measurement data they collect are useful for risk assessment, risk management, and related research activities. Research is needed to evaluate the curricula of occupational safety and health educational programs relative to exposure assessment. Research is also needed to assess the impact on curricula of external requirements, such as those of the Accreditation Board for Engineering and Technology (ABET). The results of that research will indicate the direction to take in updating curricula and course materials so that exposure assessment methods are taught effectively. Additionally, research is needed to determine the best means of communicating exposure assessment issues and results.