Session:ParcelAddress Data Maintenance

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• Session Parcel/Address Data Maintenance
• How Addresses Are Used in GIS
• Presenter Wade Kloos, ESRI
• Date Thursday, October 4, 2001

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How Addresses Are Used In GIS

• Addresses are valuable attributes for
• managing GIS features (parcels,
• businesses, utilities,etc.)

Addresses can be used to join or relate GIS data
to other agency databases (police, sales-tax and
other non-APN based datasets)
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The Search for Map Position

• GEOCODING also called
• ADDRESS MATCHING
• Depicting the relationship of a records address
  to a mapped street feature.

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GeoCoding How It Works

• Interpolating Process
• Compares a records address attribute to the
  address range of a mapped feature a road.
  

• 170 Main St.

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Scoring GeoCoded Matches
The GeoCoding process assigns a match score to
each address if the match score is over a
certain threshold, the program will map the
record.
Example Record Range
Score

• 123 Main Street 100-200 Main St.
  95
• 123 Maine St. 100-200 Main St. 80
• 123 Mane Rd. 100-200 Main St. 50/DNP
• 99 Main St. 100-200 Main St. DNP

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GeoCoding Not an Exact Science

• Placement can be affected by

• Inconsistencies of data entry process
• Subtleties of the GeoCoding scoring methods
• The interpretive process itself
• Land use patterns

• However, GeoCoding is useful when address data is
  less than perfect

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Another Address Location Option
Direct queries against GIS feature databases -
Polygons and Points
ISSUES Not a Batch Process unless custom
scripts are built No tolerance for dissimilar
addresses no interpolation Once matched,
placement is as accurate as features are mapped
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• Based on parcel polygon attributes

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• Based on point feature attributes

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Database Conventions
To maximize usefulness of address information, a
database should have the several data fields,
including but not limited to
Street Number (numerical/alphanumeric) Street
Name Street Name Prefix Street Name Suffix Unit
Number (residential apt. or condo) Suite Number
(businesses) Address combo of number, street,
suffix, etc. City Zip Zip 2,4
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Database Standards

• Standardization of addressing syntax is critical
  for consistent search results and integration
  with other application databases.
• Develop and adopt a master address database -
  from USPS or existing city databases both of
  which requires QC by staff
• Every field needs to be QC

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Database Standards

• 1st vs. First
• E. Ball vs. East Ball
• Avenida del Caballo vs. Ave. Del Caballo
• King Court vs. King Ct

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Using GIS to QC Address Data
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Using GIS to QC Address Data