Quantitative subjective assessments are almost always biased, sometimes completely misleading*

摘要: Subjective assessments are used widely in civilized societies for evaluating people, the work they do, and stresses under. Yet most of people who use subjective probably not aware pitfalls which involve. Range effects introduced by investigator almost inevitably bias quantitative assessments, unless very special precautions taken to prevent or eliminate bias. Stevens' method direct magnitude estimation is always biased range effects. The international standard calculating loudness noise corresponds a 30 decibel sound intensity. When takes introduce bias, observers may their own well-known standards bring with them investigation. In height constancy investigation conducted field, hedge fence. judging just acceptable levels, must depend upon levels accustomed to. The chief danger that be based rule does happen apply particular circumstance A result then obtained opposite truth. Examples rules heat interfere work. performance can improve both heat. Results this kind revealed measuring performance, asking how affects them. should complement measures replace