We investigate the learning of a rule from examples of the case of boolean
perceptron. Previous studies of this problem have been made using the full
quenched theory. We consider here two alternative approaches that can be ap
plied easily. The two-replicas interactions approach considerably improves
upon the well-known first-order approach. The mean field approach proved so
me results that have been obtained previously using the complex full quench
ed theory. Both approximations have been applied to both continuous weights
and discrete weights perceptron.