Suppose that Dr. Bruno obtains a significant interaction but not a significant main effect of praise. Then, in interpreting his results, he would be justified in concluding that... Suppose that Dr. Bruno obtains a significant interaction but not a significant main effect of praise. Then, in interpreting his results, he would be justified in concluding that... the effect of praise on performance depended on the level of task difficulty there is in fact a main effect of praise, but it is hidden in the data hard tasks benefit more from praise than easy tasks teachers should never criticize their students it is always beneficial to give praise