The purpose of the study was to examine the validity of unsaturated soil-water flow theory for various facets of the infiltration process, and to obtain from the validated theory more realistic and workable mathematical descriptions of infiltration processes. The research results in the report are meaningful contributions to the objective. In Section A of the report the validity of present infiltration theory is examined and shown to have some persistent failures in describing experimental measurements of horizontal water adsorption. Nevertheless, it is also shown that there is a substantial range of interest wherein the theory does hold at least approximately. In Section B of the report the validity of infiltration theory is examined for the wetting aspect of horizontal soil-water redistribution. Within a rather large scatter of experimental flux-gradient measurements, it was not possible to show consistent deviations from theory. Through several techniques of averaging it was found that reasonable reproducible characterizations of soil-water diffusivity could be obtained. (WRSIC abstract)