How Good is your Grid?
Six questions to ask when evaluating a dataset
When you’re ready to turn the magnifying glass on a land grid dataset – whether you want a better understanding of the data you’re using now, or are comparing alternatives - here are a few questions to ask yourself and your data vendor. The answers are important, and will give you a clearer picture of the dataset’s accuracy and reliability, and the vendor’s data management practices.
- Can you query each individual polygon and see when (and why) the geometry and attributes were last changed?
- What was the digitizing process used, and were the points collected within a known margin of error with respect to the source material? What is that margin?
- Can you query any polygon and establish where it came from and why a particular digitization method was used to create it? If the source material was not public information, can you still determine those answers?
- What is the process used, and frequency of updates to the dataset? How is new information incorporated – and can you easily detect changes to see where updates have occurred?
- Is the data topologically clean – free of gaps, slivers, and overlaps, with contiguous coverage? Are all polygons uniquely attributed, or do duplicates exist that will stall automated mapping processes?
- Has the dataset been adopted by leading vendors as the basis for creating their own digital products?
WhiteStar is happy to answer all of these questions for you – and any others you may have.