If this description of dual 
modes of perception is correct, 
it is no wonder that 
experiments can lead to 
varying or contradictory 
results. Subjects are caught in a 
potential conflict. If they 
match on the basis of 
constancy, they fail to take 
note of one facet of perception; 
if they match on the basis of 
visual angle (which is very 
difficult to do), they fail to take 
account of the most central 
facet, namely, constancy. Such 
an explanation sheds a 
different light on the evidence 
of individual differences in 
constancy experiments and the 
development of constancy.