Field

From EvaluationWiki

These all refer implicitly to the contrast with desk work, and desk-based evaluations. The field is where reality reminds you that it is poorly represented in words and pictures, and you have to adjust not only your descriptions of the evaluand but your designs for the evaluation, including-quite frequently-your instruments. Above all, it is the place where the ghost at the banquet, the surrounding circumstances, make themselves known, and the good evaluator becomes aware, after hard work, of the extent and nature of their control over the conclusions of the evaluation. See external validity.