The research recommendations for ozone are presented in three parts: (1) atmospheric chemistry; (2) health effects; and (3) agriculture, forests and related ecosystems. Each part is critical to setting an ozone NAAQS. The latter two areas are critical in establishing exposure-response relationships for the effects that ambient ozone produces. However, without a better understanding of exposure profiles, scientists and regulators cannot accurately establish the extent of the effects of ambient ozone exposure on public health and welfare. Without a better understanding of atmospheric chemistry, the frequency of excessive exposures or the influence of the various sources of the ozone precursors cannot be predicted.