How accurate is the data?
Points of Interest contain two measures of the accuracy of the data. Accuracy of the grid reference The grid references with Points of Interest features are located to one metre in most cases. Each record contains information to indicate how accurately the feature is positioned, for example, to the correct address, street or geographic locality. These are described in the Positional Accuracy look-up file and there is further information on how to use and interpret this information in the user guide. Accuracy of the address One of the attributes provided with each feature is the verified address attribute. The verified address attribute indicates the confidence with which the address attributes can be used, and their suitability for applications. The address information information is checked against Ordnance Survey address data, which is supplied to Ordnance Survey by Royal Mail®.
As accurate as it can get. As with any statistical data, numbers are not a 100% accurate representation of the phenomenon, but they nevertheless provide an informative description of it. For each set of statistics we perform extensive research and data mining in order to bring the most authoritative, comprehensive, and timely information to be displayed on the counters. However, numbers in most cases can’t be exact because the sources from which the data is derived, even though they are the best available in the world, are not able to provide exact numbers, but only estimates. This inherited limitation must be taken into account for the correct interpretation of the information.
I don’t know, and I don’t really have the resources to make definitive judgement of the quality. If you are just poking around for your own interest, they are probably accurate enough. If you want to do research-quality work, you really should use a professional-grade system like ArcGIS. My maps system won’t ever be better than ArcGIS, only cheaper and more accessible. Ultimately, the data comes from the U.S. Census Bureau, so it can’t be any better than the Census Bureau. Along the way, it passed through the offices of ESRI, which packaged it up in a way that made it much easier to deal with. In general, from what I can tell, it looks reasonable in most cases. By that, I mean that for the areas that I am personally familiar with, things mostly make sense. East Palo Alto has high Latino and Black populations. Milpitas and Cupertino have large Asian populations. Mountain View has lots of rental units, etc. HOWEVER, there are some areas that look really strange to me. I’ve documented som
A. Accurate data is critical to the success of your business and ours. Zip-Codes.com implements a very rigorous set of data integrity checks to ensure our database is as accurate as possible. In the unlikely event that a portion of data is confirmed as innaccurate, we will correct it within 2 business days.
