Classify the imagery—Calculate Impervious Surfaces from Spectral Imagery | ArcGIS I'm working on this Supervised classification lab on the learn.arcgis.com web site. In the "Reclassify Errors" step 4 section, I finished the classification wizard, when I wasn't finished yet. Can you go back to the "reclassify the errors" or an earlier step in the classification wizard section, or do you need to start the entire process all over again (i.e. creating training sites)? I can't figure out where to restart.