Logical consistency: No duplicate features are present. The shapefile is exported using Avenue request ExportClean. This request verifies and enforces the correctness of shapes. Horizontal position accuracy: The geospatial part of this data set was extracted from the 1990 Census Version TIGER/LineTM files (CD-ROM edition). The positional accuracy of the TIGER/Line coordinates varies with the source materials used but at best meets the established National Map Accuracy standards (+/- 167 feet approximately) where 1:100,000-scale maps from the USGS are the source. The Census Bureau cannot specify the accuracy of feature updates added by its field staff or of features derived from the GBF/DIME-Files or other map sources. Thus, the level of positional accuracy in the TIGER/Line files is not suitable for high-precision measurement applications such as engineering problems, property transfers, or other uses that might require highly accurate measurements of the earth's surface. Other data details: After processing, the data set is checked for drawing display and number of records and file sizes compared with source materials.
Notes:
U.S. Tracts provides boundaries and demographic information for U.S. Census tracts and block numbering areas. The boundaries are consistent with the county (detailed) and state (detailed) data sets. Largest scale when displaying the data: 1:100,000. Publication date: 199901, 2000; ground condition: 1990. Vector digital data. Thumbnail.
