How do you choose an appropriate address locator? The primary factors to consider are how many addresses need to be geocoded and the underlying locator data quality. Generally, web-service geocoding locators have more current underlying data, but have limits on the number of geocodes. Geocoding locators on local computer hard drives do not have limits on the number of addresses, but generally may not have current underlying data.
Therefore, the choice must be balanced based on your project needs. If the project requires fewer addresses, using a geocoding web service may the best best option. For projects with more than 10,000 addresses, geocoding web services may not be ideal so as to not be limited by the number of addresses.
When it comes to data with more than 10,000 addressed, it is also recommended to consider whether all addresses are actually needed. Additionally, removing duplicate addresses will also help with faster results. However, when removing duplicates, there are extra steps to join the coordinates back to the original dataset.
Below is a table comparing the different batch geocoding options for members of the the University of Illinois community.
| Name | Ease of Use | Costs/Limits | Web vs. Local Service1 | Geographic Scope | Currency2 | Quality / Match Scoring / Reviewable3 | More Info |
|---|---|---|---|---|---|---|---|
| ArcGIS Online World Geocoding Service |
Requires ArcGIS Online account Can be use with ArcGIS Online and ArcGIS Desktop Coding options available (JavaScript, REST) |
0.04 credits per geocode | Web, Local App vial Web | Global (Coverage Info) | Current |
High Includes match scoring Reviewable in App |
More Info |
| ArcGIS Business Analyst | Requires ArcGIS Business Analyst software and data in addition to ArcGIS Desktop |
Licensed (available on WebStore and Scholarly Commons Q: drive) |
Local | United States |
2016 2017 (coming soon) |
High Includes match scoring Reviewable in App |
|
| ArcGIS Data and Maps | Requires ArcGIS Desktop |
Licensed (available on Scholarly Commons Q: drive) |
Local | United States | 2009 |
Moderate Includes match scoring Reviewable in App |
|
| Google Earth Pro | Table must be CSV format |
Free |
Local App via Web | United States, United Kingdom, Canada, France, Italy, Germany, and Spain | Current |
High No match scoring |
More Info |
| Google Maps | Requires coding (JavaScript, REST) |
Free |
Web | Global (Coverage Info) | Current |
High No match scoring |
|
| Census Geocoder | Table must be CSV format |
Free 10,000 geocodes per file |
Web | United States | Current |
Moderate No match scoring |
|
| GeoPy |
Python coding required Can use multiple geocoders including ArcGIS, Google, and OpenStreetMap Nominatim |
Free Limits differ based on geocoder |
Web | Global | Current |
Moderate to High Match scoring dependent on geocoder |
More Info |
1Indicates whether the locator is a web service or available on a computer's local hard drive. Some web services are available through the local application, such as ArcGIS Desktop, that access a web service.
2What year(s) is the underlying locator data based on? Current means the service is generally using data from the current or previous year.
3Quality refers to the output geocoded data and is a very subjective, non-quantitative measure based on experience and knowledge of the underlying data. Match scoring refers to whether the locator output data includes a scoring value of the address match, which is helpful for assessing the data quality for each address. Reviewable indicates whether the software application utilizing the locator has a built-in geocoding review workflow or option.
What if every square inch (ok, every 3 meter square) had an unique address across the whole world...even the ocean...and it was easily understood by humans? That is the goal of what3words.
what3words is a really simple way to talk about location. We have divided the world into a grid of 3m x 3m squares and assigned each one a unique 3 word address. It means anyone can accurately find any location and share it more quickly, easily and with less ambiguity than any other system.
The service can be used via the free mobile app or online map. It can also be built into any other app, platform or website, with just a few lines of code.
How could this help your research? Imagine you are doing a survey of people at their homes in different countries and each country uses a different address system...or there is no address system. Giving people a global address could help you more easily track where the data was collected in a human readable (and computer readable) way.
what3words can also be integrated into GIS software, including ArcGIS.