The assumed rationality of consumer decision making, upon which the models largely rely, has been brought into question. In the 1980's researchers began to question the rationality of many consumer actions (Erasmus,Boshoff et al. 2001). It was found that consumers frequently engaged in non-conscious behaviours that might not be well modelled through a rational information processing approach (Bozinoff 1982, Erasmus,Boshoff et al. 2001). Other writers have found consumer behaviour in certain circumstances that appears haphazard, disorderly or opportunistic (Erasmus,Boshoff et al. 2001).
What depicts the general unreliability of these observations?