Fred Davis has heard his theories characterized as all of these -by the same person, sometimes in the same sentence - by everyone from information technology professionals to CEOs.
K. Behrenbruch, R. Kniewel, S. Niemczyk, и L. Schmidt. Useware 2012: Mensch-Maschine-Interaktion (Kaiserslautern 2012), том 2179 из VDI-Berichte, стр. 65–74. Düsseldorf, VDI-Verlag, (2012)