ArcMap Address Matching Lab
Due in two weeks
The objective of this lab is to expose you to another of ArcMap's
capabilities: address matching, sometimes called geocoding.
The notion is to convert street addresses (like 231 Nanana Street)
to coordinates. This is done by matching the addresses
against a database of street segment records, conceptually
like those in GBF/DIME, to find the data record with the best
matching street name and address range, and then interpolate
along the segment to associate a geometric point with the address.
This functionality is provided in the Geocoding Tool and
seems to require the use of a (personal) geodatabase.
In this lab you will:
Create an "Address Locator" (arc-speak for making an indexed database
out of a street segment shapefile for address matching),
match an existing file of addresses against that "Address Locator"
to produce a shapefile from the list of addresses,
plot the matched addresses on a map and examine the unmatched addresses
to gain insight into what constitutes 'problem addresses'.
practice reading the 'help' in ArcGIS.
The data have been placed on laulima, emailed to you,
and probably in the \\Odin\Data\Geog_488 server directory.
You may already have that drive "mapped" or the data copied to
your own disk.
allroad3 shapefile (in all its parts) - the Oahu street segment data
derived from Census and USGS DLG data, it has left and right
address ranges and zipcodes. (The C&C
Street data don't work as they don't have these left and right
address range fields.)
restaura.txt - a text file list of restaurants extracted from a recent
In ArcMap's and/or ArcCatalog's Help function(s),
particularly about the
address locator until you have a feel for
how Arc is going to do this. The material indexed under
"addresses, locator style" and "addressess, matching"
(the latter is an external .pdf file that tells about
the rule base for address matching) is especially useful.
Create your "address locator" from the allroad3 shapefile by
following the directions in the "Creating an address locator"
help page. Basically, in a geodatabase, save your allroads3 data and
add a new locator via ArcCatalog. The address locator style
"US Address Dual Ranges" works fairly well, then in the Field Map,
see that "FromLeft" = LEFTADD1,
"ToLeft"=LEFTADD2, "FromRight"=RGTADD1, "ToRight"=RGTADD2,
and "Street Name" = FNAME. You might experiment with other
In ArcMap, geocode the addresses by following the directions
in the "Geocoding a table of addresses" help.
(Basically, add the addresses to the project and select
Geocoding from among the "Geocoding" Tools.
Select the "address locator" and the table to geocode.
Indicate which field holds the address data and
where to save the result
(U:\Geocoding_Result_1 for instance).
Run it, and it should add the output to your map on screen.
Produce the deliverables and answer the questions below.
- A map showing the distribution of matched restaurants.
- A table showing the counts of the matched, the unmatched,
and the partially matched addresses (summarize on status)
for each of the "address styles"
- A one page write up indicating:
- what address information was in the file that you geocoded,
- which "styles" of address locators would best fit these data,
which of those you tried, and
which of those seemed to work best with these data?
- An assessment of the apparent kinds of problems the software had in
matching the unmatched addresses.
- Your observations on what might make this work better.
Help - is on the main menu and on-line.
You will be better off getting used to using it
to help solve problems than not doing so.
Making new "address locators" takes only a few seconds and greatly
affects the results. In one recent class test case, just switching from
"US Streets" to "US hyphenated ranges" increased the match rate by
more than 50%.