Our library is undertaking a project to map historical data regarding 18th and 19th century British and American printers and publishers. One of the problems that we have encountered is the different granularity of location data. For example, one publisher may list a street number, street name, and city whereas another publisher may only mention a street name or even only the city. In such cases, we are wondering the best way to georeference the location and present this approximate data.
Does the spatial humanities community have rules or conventions for dealing with these cases?
Also, what are the most effective ways for visualizing “approximate vs precise” geospatial data on the same map?