Table 2.
Distance between locations for the same address assigned by two geocoding methods, by area characteristics
| Discrepancy-distance (m) | |||||||||
| Percentiles | |||||||||
| N | Arith. mean (95% CI) | Geo. mean (95% CI) | 50th | 90th | 95th | 99th | Percent > 1 km apart | ||
| Overall | 7,686 | 160 (140, 179) | 49 (48, 51) | 54 | 180 | 296 | 2218 | 1.8% | |
| Census Tract Poverty* | ≥ 20% | 1,027 | 156 (77, 234) | 28 (25, 30) | 26 | 144 | 258 | 1370 | 1.4% |
| 10 to 19% | 2,248 | 169 (135, 203) | 46 (44, 49) | 48 | 183 | 310 | 3052 | 2.2% | |
| < 10 % | 4,411 | 156 (132, 180) | 59 (57, 61) | 62 | 187 | 300 | 1873 | 1.7% | |
| Census Tract Density* (population/km2) | ≥ 1000 | 3,770 | 106 (83, 129) | 44 (43, 46) | 50 | 134 | 174 | 717 | 0.8% |
| 500 – 999 | 1,504 | 141 (108, 174) | 50 (47, 53) | 55 | 175 | 269 | 1970 | 1.6% | |
| 200 – 499 | 931 | 213 (140, 286) | 49 (45, 54) | 52 | 202 | 333 | 5593 | 2.5% | |
| < 200 | 1,481 | 281 (218, 345) | 66 (61, 71) | 70 | 401 | 779 | 5548 | 4.1% | |
| Most common reference for multi-stage method* | Local Parcels | 4,644 | 152 (128, 176) | 61 (59, 62) | 63 | 172 | 258 | 1704 | 1.5% |
| Local Roads | 1,075 | 136 (107, 165) | 52 (48, 56) | 53 | 193 | 333 | 1667 | 2.0% | |
| TIGER-based | 1,967 | 191 (140, 242) | 30 (28, 32) | 25 | 211 | 414 | 4028 | 2.5% | |
Discrepancy-distance indicates distance between multi-stage and single-stage geocoded address coordinates for the same address; p50, p90, p95, and p99 indicate the 50th, 90th, 95th, and 99th percentiles; TIGER indicates Topologically Integrated Geographic Encoding and Referencing system line files, this includes NAVTEQ and Dynamap reference files
* Indicates significance (p < 0.05) for a comparison of discrepancy-distances across subgroups using a linear regression model