Abstract
Five autisitic children were trained to report "private events" in various play situations. Conditional discrimination training was conducted to establish two verbal behavior : "pleasant" and "exciting." "When children played with pleasant materials, such as big ball, they were required to report the listener "pleasant." When children played with exciting materials, such as balloon, they were required to report the listener "exciting." A11 children acquired such tacts for "private events." These tacts were emitted for non-training materials and for another persons including their mothers. These results suggest that acquisition of tact was not based on children's "mental state, " but on the conditional response to external play materials.
