Discusses methods for plotting rates of photosynthesis as a function of light quantity. Presents evidence that suggests that empirically derived conversion factors, which are used to convert foot candles to photon fluence rates, should be used with extreme caution. Suggests how rate data are best plotted when any kind of light meter is not…

Describes an assay to determine the rate of photoreduction of 2,6-dichlorophenolindophenol (DCPIP). Acquaints students with experimental design and teaches them how to evaluate and communicate their results with the goal of enhancing their scientific literacy by integrating basic chemistry and arithmetic into their practical experience. (JRH)