critics like carey pointed out that the hawthorne group selected in their first experiment 'cooperative' girls who were willing to participate in the research programme and this type of research was 'worthless' , since a sample of five or six cannot be taken as a reliable sample to make generalisations. carey also observed that the evidence obtained from the experiments does not support any of the conclusions derived by the hawthorne investigators. there exists a vast discrepancy between the evidence and the conclusions. on the other hand, the data only supports, according to carey, the old view of monetary inncentives, leadership and discipline as motivating factors for better performance. he also criticised hawthorne's investigations for their lack of scientific base.