Estimating the Magnitude of Private Collection of Points and Its Effects on Professional Survey Results

Abstract

ABSTRACTChipped-stone projectile points are used to mark the passage of time and cultures in the record. Archaeologists often recover points in surface survey, yet we do not know how many were found by private collectors before or after professional work. In a 1975–1977 Michigan probabilistic survey, professional archaeologists documented 30 private collections from 20 sample units. In those units, points found by private collectors outnumber professionally recovered ones by a factor of about 32. The survey region's point population estimated separately from the professional and private-collection samples differs by nearly an order of magnitude in favor of private collections, despite highly conservative assumptions about the latter. The number of points found in professional survey is inversely correlated with the number found in private collections, and the professional sample is more sparsely and randomly distributed. However, proportions of several common types are similar between professional and private collections. To the extent that large, reasonably complete samples of points are important for research and preservation, archaeologists must document private collections compiled in and near their survey areas.