Developing An Effective Appraisal Program Criterion Contamination Performance standards should not be influenced by factors outside the employee's control.For example,if an employee's performance is affected by bad materials or poor equipment,his or her performance standards may be contaminated.Developing An Effective Appraisal Program Criterion Contamination - Performance standards should not be influenced by factors outside the employee’s control. For example, if an employee’s performance is affected by bad materials or poor equipment, his or her performance standards may be contaminated