The archaeometrist in the laboratory needs to know the ecological constraints of the materials with which he/she is working, and the ethnoarchaeological opportunities of the area. Examples of influences upon variations in results by site characteristics are mentioned. Sample description needs to be as complete as possible: variables in color and texture are some features which must be noted in published reports. Data should be reevaluated at intervals to see whether they still hold up in view of current knowledge and constraints. Radiocarbon dates should be classified according to their reliability. A proposal for a Repository of Archaeological Technological Materials to be established at the Smithsonian Institution is set forth: a catalog of where the material that has been studied is stored if not at the Smithsonian. -- AATA