(DIGSS) Determination of Intervals using Georeferenced Survey Simulation: An R package for subsurface survey.

Systematic survey is a crucial component of the archaeological field endeavor. In low visibility areas, systematic subsurface testing is required, most often in the form of shovel test pits or "STPs". Decisions about the interval between STPs, and the size of such units, impact significantly both the effectiveness of survey for site location and the efficiency of such prospection efforts, and yet "cookie-cutter" survey strategies are often employed without a thorough examination of their costs and benefits. In this work, we present a simulation-based method (DIGSS, Determination of Intervals using Georeferenced Survey Simulation) by which archaeologists can simulate the effectiveness and efficiency of different survey strategies for both prospective and retrospective applications. Beyond permitting the design and implementation of survey strategies that both maximize the possibility of site detection in a given region and that husband precious resources (money and time), this method permits the generation of post hoc correction factors that make direct comparison of previous surveys possible. While DIGSS was designed with archaeological applications (artifacts and sites) in mind, it has potential ramifications in other fields of study where discrete spatial sampling is used as a means of determining the presence, absence, or abundance of discontinuous assemblages materials of interest in a survey region. As such, we can envision potential application in the fields of geology, ecology, and environmental/pollution monitoring.