I have a student working in my GIS lab who is computing an IDW interpolation surface for observations taken from a boat moving along a series of paths. The sampling paths were not uniform over the entire study area for a variety of reasons, meaning there are more samples in certain areas, and fewer in others.
Because the inputs are not uniformly distributed the assumption is the output interpolation is more correct in densely sampled areas than in lightly sampled areas. The student would like to visualize that sampling error or confidence level.
What methods are typically used to visualize error or confidence in interpolated surfaces based on input distribution?
Would a simple density surface be adequate?