The report describes general theoretical frameworks for the ordering of diffusion field data in terms of meteorological measurements. The three methods described are surface-layer (Monin-Obukhov) similarity, convective scaling, and statistical theory using wind fluctuations. Early analyses of historic field experiments are reinterpreted in terms of these frameworks and many examples of analyses using these three methods are cited from the literature. The strengths and limitations of each method are discussed at length and the most effective methods are identified according to stability, height of source, and vertical or lateral diffusion.