At optical wavelengths the solar flare is a very complex phenomenon, and one of the major problems in the study of solar flares has been to find a consistent and reliable method of classifying them. A survey of the published data will quickly show that a solution has still to be found. A second problem is to find some parameter which will accurately represent the temporal variation of the flare. The relatively small amount of photometric measures available shows that there is a need for a rapid method of characterizing the flare’s intensity and areal fluctuations. In comparison to other astronomical measurements, the techniques used in measuring and classifying flares are primitive and highly subjective. The present system of classification differs only slightly from the pioneering efforts, and little attempt has been made to take advantage of the technological developments to remove the observer’s subjectivity—in fact, the latest classification scheme actually increases it!