To make mistakes is not desirable. To believe that no mistakes are made is naive. To repress mistakes is not credible. To not know the mistakes takes away the opportunity to improve upon them. To loose track of the mistakes can lead to wrong estimates and conclusions.
The control survey, which was conducted in the framework of the terrestrial survey for the second National Forest Inventory (NFI), served to detect errors and shortcomings as well as to quantify, to evaluate, and if possible, to eliminate them (see Chapter 2.8).