Large differences have been found between different field-workers when they make vegetation maps of the same area. It is difficult to know which map is 'correct' in these cases, but by gathering a group of field biologists and letting them decide on a 'correct' reference mapping unit, this paper presents a method for evaluating just that.
In 2016, 11 field-workers mapped 120 points, marked with plastic sticks. First, they individually and in secret decided on what NiN mapping unit the point belonged to. Then, the group discussed the point and reached a reference mapping unit for the point. The individual and reference mappig units for each point were compared, yielding an estimate of 35 % error in mapping-unit assignment.
The paper is based on the master thesis of Eriksen, and the field effort of the authors plus Johnny Hofsten and Espen S. Værland.
