I'm trying to find the best interpolation method for a project I'm working on. I've tried the basic settings with spline, IDW & kriging and they all appear ok at first glance, but when I look more closely they don't follow the points exactly like they should. For example, I will have a point or cluster of points with a value of 59, and a neighboring point or cluster of points with a value of 60. When I adjust the symbology to 59.5 I would think the line would be drawn evenly between the two points or clusters of points every time. In some cases the line is drawn between the two, but in other cases it is not. The resulting map is "generally" correct, but with a lot of little errors here and there. I'm not real familiar with how interpolation works exactly, and I want to know if one of the methods would be more accurate or have less errors for the particular project I'm working on. I will have 20,000+ points over an area the size of Florida (if that even matters).