Data Quality – University of Colorado at Boulder
Great Site for Describing Data Quality
Review of Accuracy and Precision for Spatial Entities
From the slide we looked at in tutorial (and the data we saw in lab this week), we can see that how data sets (different layers) can be different from each other in terms of accuracy and precision. We also discussed the difference between accuracy and precision. Remember there are lots of sites on the web discussing these issues, so look around. We looked at the one on ESRI’s wiki site:
Discussion on Error and other topics that influence our use of data in mapping and GIS
Lets look a a web page written by Kenneth E. Foote and Donald J. Huebner (the Geographer’s Craft Project, Department of Geography, The University of Colorado at Boulder – 1995).
Has a more in depth way of looking Accuracy and Precision
They look at the concept of error
Not just positional and attribute, but also consider Conceptual and Logical error – we have talked about bias for instance
This information was put forth 21 years ago – before Scott worked in GIS – but ideas are still applicable.
The world wide web was not around or even considered documents such as Foote and Huebner’s. What effects would we need to consider with contemporary internet use?
How are problems integrated into data quality – Introduction and propagation of Error Difficulties in measuring objects
People, processes and hardware can increase error and lower quality
Meta Data that is truthful
search out meta data
create meta data when you make a new layer