Archaeologists have used maps for quite a long while, and with good reason. People, their communities, and their things are situated in places. The context of artifacts and biological remains are critical to understanding the human past.

Flip open most archaeological journals and you’ll find a map. During the spatial turn, we incorporated geospatial technologies that let us pinpoint features with precision and extract new information from complex spatial patterning.

Folks in the health and medical sciences have also embraced the power of location for some time. At this point it’s almost cliché to point out the significant impact of John Snow’s 1854 mapping of a London neighborhood showing the proximity of household cholera deaths to a shared water pump (John Snow: A Legacy of Disease Detectives. Today, we’ve all seen the interactive Covid-19 maps used to understand the spread of the disease (For example, the Covid-19 atlas).

Studies that incorporate medical and personally identifiable information (PII) are heavily regulated by federal law and institutional policies to prevent violations of privacy. The enactment of the Health Insurance Portability and Accountability Act (HIPAA) in the 1990s, encouraged the development of additional methods for sharing findings through anonymization methods to adhere to the law. Geomasking is set of techniques that allow researchers to use the power of maps while retaining anonymity for individual study participants.

Archaeologists work under a different set of legal and ethical constraints. The locations of some archaeological sites are legally restricted, while the sharing of other site locations is at the discretion of the researcher, unit, agency, or institution. How do we balance legal and ethical obligations to obscure sensitive archaeological sites and continue to share the insights provided by geospatial technology? Much like public health, archaeologists heavily – and often implicitly – rely on two geomasking techniques: aggregation and low-resolution mapping. In my paper Ethics and Best Practices for Mapping Archaeological Sites I compare these methods, and others, to identify how effective they are in obscuring real-world locations while retaining fidelity to observed spatial relationships.

While there are some clear winners in terms of effective geomasking techniques for archaeology, the critical implication of my findings is that how archaeologists represent site locations in a static map or a shared dataset should be an explicit decision. Archaeologists and information professionals are already hard at work developing methods to appropriately integrate archaeological data across administrative boundaries and into open data frameworks. It is imperative that we establish best practices to adhere to existing legal regulations and professional ethical standards as we work to increase access to data collections and spatial information.

Cecilia Smith is the GIS & Maps Librarian at the University of Chicago where she directs the Map Collection and GIS Hub. Cecilia’s research focus is on the use of historical geospatial data and issues of data ethics and privacy. She received her MSc from University College London and PhD from the University of Illinois at Chicago. Her paper Ethics and Best Practices for Mapping Archaeological Sites is available to read free of charge until 31 July 2020 in the current issue of Advances in Archaeological Practice.