the forced distribution method creates problem for evaluators who believe that the pattern of performance form people being evaluate does not conform to the fixed percentages. regardless of the approach, norm-referenced methods usually measure performance using one criterion-overall performance. this global measure isn't anchored in an objective index, such as units sold, so results can be influenced by subjective biases that have little to do with actual performance. because the rankings lack behavioral specificity, they may be subject to legal challenge. other problem with norm-referenced approaches are that they provide no information about the absolute level of performance, and they provide no useful information for the job incumbent to act on.