Accuracy Assessment of an Image Classification in ArcMap 

This tutorial demonstrates how a confusion matrix is created to assess the accuracy of an image classification. You begin by selecting an appropriate number of test pixels, and creating a point shapefile in ArcCatalog to begin assigning reference points. This video will walk you through the process to accurately assessing the classification of your image.
Credits & Attribution: Maps & GIS, Evans C. Sterling Library, Texas A&M University