This study was designed to determine whether the acquisition of second-orde
r conditional discriminations becomes more rapid across new discriminations
. Three normal grade-school children served as subjects. In general, perfor
mances improved across sets of second-order discriminations. Moreover, ther
e was little disruption of performance when the second-order stimuli were c
hanged from discrete forms to being compounded with the sample stimuli. Err
ors increased markedly when the second-order conditional discrimination shi
fted from one in which one second-order conditional stimulus indicated that
the original contingencies were reversed to a condition in which one secon
d-order conditional stimulus indicated that the subject should select the s
ame comparison stimulus regardless of which sample form was present. Errors
prior to mastery decreased, however, across problems of the new type-thus
reproducing the learning-set outcome with new stimuli.