Stability of direct and transfer effects of number-conservation training with mentally retarded adults.

Twenty nonconserving retarded adults were assigned to equated training and control groups (n = 10 in each group). Training-group subjects were given multiple-strategy training for number conservation consisting of: demonstrating effects of addition-subtraction; negation of addition-subtraction by inverse operations; and addition-subtraction combined with perceptually induced cognitive conflict, reversibility, and verbal-rule instruction. Analyses of variance and critical difference multiple comparisons showed significant direct-training effects immediately after training and after 8 monhts. Significant short-term transfer was obtained on other types of conservation (discontinuous quantity, substance, liquid quantity, length, and weight), but long-term transfer was much weaker and less consistent. Transfer resulted primarily from gains in correct conservation judgements, with a majority of trained subjects failing to give any acceptable conservation explanations.