Reply to the comment by Patterson (See also <i>AATA</i> 28-) concerning the role of thermal alteration in the lithic technology of Bald Eagle jasper from central Pennsylvania. Several points made by Patterson are interesting; however, other aspects of his critique are not relevant to the research presented. This reply reemphasizes the physical and chemical changes resulting from the heat treatment of Bald Eagle jasper, reexamines the lithic manufacturing process represented at the Houserville site, and presents the authors' view of the role of replicative experimentation in lithics research.