A researcher compared Learning outcomes of behavior-disordered, attention-deficit, and developmentally delayed children after they had all received computer-assisted instruc¬ tion (CAI) in reading comprehension

A researcher compared Learning outcomes of behavior-disordered, attention-deficit, and developmentally delayed children after they had all received computer-assisted instruc¬ tion (CAI) in reading comprehension. He found that the behavior-disordered children had the best reading comprehension scores on a test given after the CAI treatment. What problems do you see with his conclusion that CAI is more effective for behavior-disordered children than for attention-deficit and developmentally delayed children?