Data Issues

Data Issues

Overiew:

In most GIS projects, 85% of the total project effort revolves around:

This project is no exception!

Data Sets:

*Data sets being used*
Data Set	Type	With data?
Census Blocks	Polygon	Yes - census attributes
Block Groups	Polygon	Yes - census attributes
United Way Program Sites	Point	Yes - services provided
Juvenile Court	Point	Yes - court referral reason
Health Department (infant mortality)	Point	unsure
Superfund	Point	Minimal
Toxic Release Inventory (TRI)	Point	Minimal
Churches	Point	No
Businesses	Point	Minimal
Streets	Line	No
Bus lines (GRATA) (G.R. only)	Line	No

*Data Sets NOT being used*
Census Tracts	Polygon	Yes - census attributes
Zoning (G.R. only)	Polygon	No
Parcels (G.R. only)	Polygon	No
Renaissance Zones (G.R. only)	Polygon	No
Historic Districts (G.R. only)	Polygon	No
Neighborhood Associations (G.R. only)	Polygon	No
School Districts	Polygon	Yes
Railroads	Line	No

Samples of
Data Issues

Data File:	United Way Programs

Problem:	Poor organization of original data base (Illustration 1 below)
	Data set contained 3,087 rows of data Many organizations used multiple rows of data One row for each program service, not address Thus, multiple services offered at a single address were listed in multiple rows

Fix:	Sort databse on two fields: Organization name Organization address In the end, there were 577 unique organizations.

Current Deficiency:	Database of organizations only - can't be queried by service type.

Problem:	Poor data entry (Illustration 1 below)
	Many addresses were entered incorrectly

Fix:	Manually go through each of 3,087 rows and do the following: Delete rows with incomplete information Extract rows not in Kent County Edit obvious errors

Current Deficiency:	Of 577 remaining organizations, 108 (19%) were not able to be geocoded properly.

Illustration 1: Database Problems