For any measurement program that collects analytical data over a long period of time for comparative purposes, the quality and credibility of those data are critical (Taylor, 1988). It is equally critical that the data can be easily understood by the user. The uses of these data include, but are not limited to, routine soil characterization, special analyses, soil classification, interpretations, and soil genesis and geomorphology studies. Because of the diverse uses of these data, it follows that pedon characterization data, or any soil survey data, are more appropriately used when the operations for collection, analysis, and reporting of these data are well understood. Results differ when different methods are used, even though these methods may carry the same name or concept. Comparison of one bit of data with another is difficult without knowing how both bits were gathered. As a result, operational definitions have been developed and are linked to specific methods.