This document discusses 8 different interpolation methods in ArcGIS: IDW, Kriging, Natural Neighbor, Spline, Spline with Barriers, Topo to Raster, Trend, and Topo to Raster by File. IDW estimates cell values by averaging sample data points weighted by distance, with closer points having more influence. Kriging generates an estimated surface from scattered points using geostatistics. Natural Neighbor interpolation assigns weights to closest input samples based on proportionate areas. Spline and Spline with Barriers create smooth surfaces that pass through input points, with Spline with Barriers honoring discontinuities. Topo to Raster and Topo to Raster by File create surfaces that