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Geographic Information Systems at Yale: Geocoding Resources

Geographic Information Systems at Yale University encompasses a range of spatial applications and services. GIS is used by many disciplines at Yale University.

Geocoding of Street Addresses and Administrative Boundary Levels

Geocoding APIs

Geocoding Services and Software to Determine Coordinates and Uncertainties in Text-based Localities

Simply put, Geocoding is the process of assigning a set of coordinate pairs (combined to create points, lines or polygons) that describe the locality of some object or phenomenon. The most familiar form of geocoding is performed when you enter an address into Google Maps, MapQuest or other online street mapping platform, and a point on a map is returned to you. However, street addresses are not the only locality types that are subject to the geocoding process. Localities referring to various administrative boundary levels (state, district, province, postal code) and even localities with varying levels of specificity (directional offsets from known locations, distances along paths, etc...) can be geocoded and, importantly, qualified with some level of geometric uncertainty. In the research context, geocoding is generally done as a batch process, though it is generally an iterative one, requiring some manual quality control and fine-tuning for best results. The resources and tools listed here are those that I have found useful in various types of geocoding processes.


In general, these are searchable databases of toponyms (geographic placenames).