greenstein suggests the F-scale is 'a comedy of methodological errors', for example items are worded in the same 'direction', so the scale just measures the tendency to agree to everything. also, researchers knew the participants' test scores when they interviewed them. so they knew who had authoritarian personalities. they also knew the study's hypothesis, which makes biased results likely. this suggests that the data collected is meaningless and the concept of authoritarian personality lacks validity.