Setting up and running Accuracy Assessment

You can evaluate the overall accuracy of a supervised classification by running Accuracy Assessment. This operation compares a reference field, generated by editing training sites, and a classification field (generated by running a classification.

The reference field and the classification field must be of the same segmentation file. When a segmentation file contains several reference and classification fields, it is a good practice to compare a classification with the reference field used to create it.

To set up and run Accuracy Assessment

In the Object Analyst window, in the list under Operation, select Accuracy Assessment.
The display is refreshed to show the settings for an accuracy assessment.
Under Classified Results, beside the Classified vector layer box, click Select, and then in the Layer Selection window, do the following:
- In the File box, type or select the file you want.
  If the file you want does not appear in the list, click Browse, and then select the file you want.
- In the Select column of the table, click the vector layer you want.
  That is, select a polygon vector layer that contains class information (class field). After you select the layer, a check mark appears in the Select column.
- Click OK.
Under Classification field, select the attribute of the vector layer that contains class flags you want to use.
Under Reference field, select the field in the vector layer that contains class flags for the reference polygons.
Do one of the following:
- To add the operation to the Process Canvas box, click Add.
- To add the operation to the canvas and run the process, click Add and Run.

If necessary, after setting up and running an accuracy assessment, you can create a report and export it. For more information, see: